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Mr. M's Textbook Notes

 

 

 

 

Mr. M’s Conceptual Physics Text Notes

(2009 Edition)

 

 

Taken and Listed in Probable order of introduction through the year

 

 

While I hope they’re helpful to you; do not let these notes STOP YOU from taking your own notes;

 

 

I know different things than you do

so my notes and yours might not even be close!


Contents

Chapter 1 – About Science                                                                           

Chapter 2 – Mechanical Equilibrium

Chapter 3 – Newton’s First Law of Motion – Inertia 

Chapter 4 – Linear Motion

Chapter 5 – Projectile Motion

Chapter 6 – Newton’s Second Law of Motion – Force & Acceleration

Chapter 7 – Newton’s Third Law of Motion – Action & Reaction

Chapter 8 – Momentum

Chapter 9 – Energy

Chapter 10 – Circular Motion

Chapter 11 – Center of Gravity

Chapter 12 – Rotational Mechanics

Chapter 13 – Universal Gravitation

Chapter 14 – Satellite Motion

Chapter 15 – Special Relativity – Time & Space

Chapter 16 – Special Relativity – Length, Momentum, & Energy

Chapter 17 – The Atomic Nature of Matter

Chapter 18 – Solids

Chapter 19 – Liquids

Chapter 20 – Gases

Chapter 21 – Temperature, Heat, & Expansion

Chapter 22 – Heat Transfer

Chapter 23 – Change of Phase

Chapter 24 – Thermodynamics

Chapter 25 – Vibrations & Waves

Chapter 26 – Sound

Chapter 27 – Light

Chapter 28 – Color

Chapter 29 – Reflection & Refraction

Chapter 30 – Lenses

Chapter 31 – Diffraction & Interference

Chapter 32 – Electrostatics

Chapter 33 – Electric Fields & Potential

Chapter 34 – Electrical Current

Chapter 35 – Electric Circuits

Chapter 36 – Magnetism

Chapter 37 – Electromagnetic Induction

Chapter 38 – The Atom & The Quantum

Chapter 39 – The Atomic Nucleus & Radioactivity

Chapter 40 – Nuclear Fission & Fusion

Appendix A – Units of Measure

Appendix B – Working with Units in Physics

Appendix C – Graphing

Appendix D – Vector Applications

Appendix E – Exponential Growth & Doubling Time

Appendix F – Equations of Physics

Appendix G – Preparing for a Career in Physics 

 


Chapter 1 – About Science

 

1.1 - The Basic Science – Physics

1.2  - Mathematics – The Language of Science

1.3 – The Scientific Method

Hypothesis – predict outcome, perform exp, formulate law

1.4 – The Scientific Attitude

Fact – agreement among observers

Laws/Principle fact not contradicted

Theory – large body of info all points to same thing: atomic/cell theory

1.5 – Scientific Hypotheses  Must be Testable

1.6 – Science, Technology, and Society

1.7 – Science, Art, and Religion

1.8 – In Perspective

 

 


Unit 1 – Mechanics

 

Chapter 2 – Mechanical Equilibrium

 

2.1 –  Force

          One needed to change an objects state of motion start it, stop it.

          Net force, combined forces, resulting motion.

          Tension & weight.

          Vector magnitude AND direction.

          Scalar Magnitude ONLY.

           

2.2 –  Mechanical Equilibrium

          Σ Force = 0.  Net Force ZERO.  Moving or not irrelevant.

2.3 – Support Force

          Also called “Normal” Force, upward force of something sitting on a

Surface.  Foot on floor; floor on foot.

2.4 – Equilibrium for Moving Objects

          Static Equilibrium = not moving;

Dynamic Equilibrium = moving at a constant speed ... straight line (no

turning for equilibrium.)

2.5 – Vectors

          Parallelogram Rule for resolution of vectors.   


 

Chapter 3 – Newton’s First Law of Motion - Inertia

 

          3.1 – Aristotle on Motion

                   Natural Motion (straight up or straight down)

Violent Motion (imposed – pushed or pulled)

          3.2 – Copernicus and the Moving Earth

                   Sun/Earth @ the CENTER of everything

          3.3 – Galileo on Motion

                   Force = Push or Pull

                   Friction = irregularities between materials that are touching

                   Figures 4.2 and 4.3, page 45

          3.4 – Newton’s Laws of Inertia

                   First – Law of Inertia; not going doesn’t, going then keeps going

(air hockey)

          3.5 – Mass – A Measure of Inertia

                   Mass (quantity of matter) is not Volume,

Mass is not Weight (force of gravity on a quantity of mass)

1kg = 9.8 N

          3.6 – Net Force

                   Force vectors, which direction wins

          3.7 – Equilibrium – When Net Force equals Zero

                   Support/Normal Force = Balanced = NO motion

          3.8 – Vector Addition of Forces

                   Force (N) & Angle

          3.9 – The Moving Earth again

                   CopernicusEa moving, Birds can’t catch worms (dist covered)

                             Ea must be at rest, ie center of everything

                   Need to consider Inertia: Bird, tree, worm all travel same speed

                   Jump next to wall CRUSHED … not.  Inertia …

                   Coin – up & down (gravity), Hz (inertia – leaves hand moving at 30km/s)

                   Aristotle – Less Inertia only one set of rules not his two (Ea vs. “heavens”)

                             Friction not recognized.

                   Galileo/Newton – same rules (one set); moving happens w/out friction

 


Chapter 4 – Linear Motion

 

          4.1 – Motion is Relative

                   Frame of reference; compared to you, me, room, NA Plate, Ea,

Sun, Solar System, Galaxy, or Universe.

          4.2 – Speed

                   distance/unit time.  Instantaneous (what speedometer says

                             …now) and/or average.

          4.3 – Velocity

distance/time WITH Direction (North, South, or Right

Ascension and declination.)  Constant (speed and

direction) or changing (either speed or direction.)

          4.4 – Acceleration

                   Change in VELOCITY speed-up, slow-down, turn corner, or

Orbit.  Accel. = change in speed (or d/t) / time = m/s2.

          4.5 – Free Fall: How Fast

                   Instantaneous speed = Accel. (due to G)  X  Elapsed time

           (v [m/s]         =     g [m/s2]            X            t [s])

          4.6 – Free Fall: How Far

                   Ave Speed = Beg Speed + Final Speed/2

                   Acceleration = Change in Speed/Time Interval

                   Distance = Ave Speed X Time Interval

Distance = Beg Speed + Final Speed/2 X Time

          4.7 – Graphs of Motion

                   Linear – Proportional. 

Non-Linear = Curved = (parabolic/squared.)

          4.8 – Air Resistance and Fall Objects

                   Mass not important; light is slowed, dense is not slowed.

          4.9 – How Fast, How Far, How Quickly How Fast Changes

                   Speed/Velocity = v = gt = How Fast

                   Distance = d = ½gt2 = How Far

 


Chapter 5 – Projectile Motion

 

          5.1 – Vector and scalar Quantities

                   Magnitude AND Direction = Vector Quantity.  Vel., Accel., & Force.

                   Magnitude ONLY = Scalar Quantity.  Masses.  Can be +,-, x, & /. 

          5.2 – Velocity Vectors

                   0°, 45°, 90°.  Additive, Subtractive.

          5.3 – Components of Vectors

                   One into 2 vectors; resolution of the vector (to vectors.)

          5.4 – Projectile Motion

                   Ball, stone, satellite; various “curved” paths. 

                   Fall or tossed out land same time.

          5.5 – Upward Launched Projectiles

                   Figure 3.10, pg 35; d = ½gt2

                   Vectors used for resolution of forces/gravity along path.

          5.6 – Fast-Moving Projectiles – Satellites

                   Path = Ea curvature (no wind resistance so keeps going, less gravity.)

                   Escape = 8km/s = 18,000mph!

 

 
Chapter 6 – Newton’s Second Law of Motion – Force and Acceleration

 

          6.1 – Force Causes Acceleration

                   Puck at rest, hit it, it moves; stick = force; force causes acceleration

                   Accel ~ net force (Proportional to)

          6.2 – Mass Resists acceleration

                   Acceleration ~ 1/Mass (Inversely Proportional)

          6.3 – Newton’s second Law

                   Second – Accel from net force ~ to magnitude of net force

inversely proportional to mass of object. (a = F/m)

          6.4 – Friction

                   Solids, Fluids (air).  Just right balanced no accel.

          6.5 – Applying Force – Pressure

                   Pressure = F/area (1N/m2 = 1 pascal)

          6.6 – Free Fall Explained

                   2 masses close (and decent) fall same rate (2 rocks vs. rock/feather)

                   Aristotle – 1kg rock & 10 kg rock (10 kg = 10X faster than 1 kg Nope)

                   NewtonF/M = F/M = g (9.8m/s2 on Ea)

          6.7 – Falling and Air Resistance

                   Terminal Speed – fastest speed w/out direction

                   Terminal Velocity – fastest speed in some direction … down …

 


Chapter 7 – Newton’s Third Law of Motion – Action and Reaction

 

7.1 – Forces and Interactions

          Push or pullON something (nothing NO Force) Hammer/Nail.

7.2 – Newton’s Third Law

          ActionReaction A Push is meet by an equal and opposite push.

          Neither exists w/out the other, occur in pairs.

Stand on floor, floor pushes back.

7.3 – Identifying action and Reaction

          ID the interaction FIRST

Ea on boulder = action then boulder on Ea = reaction

Forces here ARE equal

7.4 – Action and Reaction on Different Masses

          Ea “falls” to boulder, boulder “falls” to Ea

          Rifle/Bullet equal & opposite;  Bullet:  F/m = a;  Rifle: F/m = a

                Recoil (kick) = bullet out the other end. Wrist/Arm/Shoulder pain.

          Machine gun/Rocket both “climb” …

          Thrust – Lift – Drag – airplanes/birds

7.5 – Do Action and Reaction Forces Cancel?

          External Forces – Seems not to cancel but ALL considered …

          Force can be converted to motion, heat, etc. Will be conserved.

7.6 – The Horse-cart Problem

          Why does the cart move = and opposite pull from cart on horse ..

          Frames of reference farmer (the cart), horse, and cart/horse.

                   Cart – net force/mass – produces acceleration cart goes.

                   Horse – interacts with ground … could go faster w/out cart

                                Horse pushes on ground; ground pushes on horse

                                      This net force larger than cart, cart goes.

                                      Moving – horse only need overcome friction

You got to love wheels!

                             Horse – Cart one system, forces internal, equal:

                                      “System” interaction with the ground makes the cart go.

                   Car stalls – no need to push on the dashboard to make it move again.

7.7 – Action Equals Reaction

          The way you touch something is the way something touches you.

                   Caress/Caress, slap/slap, hit/hit; you get back what you give

(with a wall – you get more some broken bones, etc.)

 


Chapter 8 - Momentum

         

8.1 – Momentum

                   Mo = Mass X Velocity; Stand in front of stopped car or a speeding car?

                   Mo = Mass X Speed (if direction not important)

                   (Ch 11.6) Angular Mo = rotational inertia x rotational velocity = I x ω

 

          8.2 – Impulse Changes Momentum

                   Change V (less likely M) and acceleration occurs, result of force.

                   A = more change with more time of applied force.

                   Impulse = Ft = change in Mo = Δ(mv) [a= Δv/Δt; F/m=Δv/Δt; FΔt= Δ(mv)]

                   Impulse = Ns; Impact = N

                   Case 1 – great force long time golf club-golf ball no force till impact.

                   Case 2 – decrease force, increase impact time haystack or airbag (mv => Ft)

     vs. wall (mv => Ft) ouch!

     Ft = Δ Mo = caress (moving AWAY from Force)

      Ft = Δ Mo = ouch! (moving TOWARDS Force)

     Circus net = extends ttttttttttttttttttttttttttttttttttt to fall/bounce.

          8.3 – Bouncing

                   Greater Force than just splat/break/no bounce.  Catch AND throw.

                   Pelton – allowed water to bounce back out, used more of the waters energy

(more efficient)

7.4 – Conservation of Momentum

          Rifle not moving b4 shot not moving after mo conserved (bullet

inside system, can’t effect mo of system.)

Force must be external to cause change in mo (car hit by car – yes)

(push on dashboard – no)

                   Mo has magnitude and direction, vector quantity

                   Internal system Mo conserved (stars explode, cars crash,

nuclei decay); External is another subject

7.5 – Collisions

          Mo before = Mo after (Vectors – Short becomes long,

long becomes short, system the same – Conservation)

mv before = mv after

Elastic – Perfect balls (do not deform) – Don’t see as heat/crunch happens

Inelastic – Trains moving and not.

Problem – page 97 – two fish and lunchtime.

7.6 – Momentum Vectors

          Crash cars fireworks, elementary particles – Vectors work

          Car in @ zero, car in @ 90 cars out @ 45

 

Chapter 9 – Energy

 

9.1 – Work

          Equals Force X Distance [Joules] (force x time = impulse)

                   Nm = Joule = unit of torque SAME as torque but very different

(like degrees and degrees, sort of)

(work in direction of motion; torque to direction of motion)

 9.2 – Power

          Twice power = twice work

          Work/Time = J/s = watts

          1w = 1J/s

          1hp = 0.75kW; 134hp = 100kW

9.3 – Mechanical Energy

          Shake sand – make heat

Available energy due to position of something or movement of something

9.4 – Potential Energy

          Spring – stretched/compressed

          Rubber band – stretched/compressed

          Chemical energy – gasoline (a little flame can go a long way)

          Elevation = Gravitational Potential Energy

          PE = mgh = weight (not mass) x height - [get there by stairs,

elevator, inclined plane]

9.5 – Kinetic Energy

          Energy of Motion

          KE = ½mv2

          Fd = ½mv2,  net Force x distance = Kinetic Energy

9.6 – Conservation of Energy

          (energy version of Conservation of First Law of Thermodynamics, Ch 24.2)

          How it transforms to motion to heat to whatever

          cannot be created or destroyed(?) Quantum issues

but moves around in various ways to various places

                   Pendulum …. Galaxy

                            high = hi PE; bottom swing = hi KE; and half-way is half-way

                   Sun nuclear to radiant; reactor - nuclear energy to heat

9.7 – Machines

          Multiplies Force or changes direction of Forces

Levers – work input = work output

               (Force x distance) input = (Force x distance) output

          Fulcrum – pivot point – multiply force (big time!)

          Mechanical Advantage – ratio input force to output force

 

Chapter 9 – Energy (Continued)

 

Type (class) 1 – I, F, O – teeter-totter

          Type (class) 2 – F, O, I – turn car over

          Type (class) 3 – F, I, O – arm, elbow

          Pulleys – lever that changes direction of force –

                   I, F, O

                   F, O, I

                   I, F, O + F, O, I = double pulley (change direction, multi forces)

     Plus – more ropes to continue multiplying Input force 

9.8 – Efficiency

          =  useful work output/total work input

          =  actual mechanical advantage/theoretical mechanical advantage

          Inclined Plane, Auto Jack,

Auto Engine (Chemical to Mechanical and unfortunately Heat)

9.9 – Energy for Life

          Hydrocarbons release energy that is stored in cells, catalysts

speed Process

                   Photosynthesis – Energy input (sun) makes sugar and O2.

 


Chapter 10 – Circular Motion

 

10.1 – Rotation and Revolution

          Rotation around an internal axis – a day

          Revolution around an external axis – orbit/a year

10.2 – Rotational Speed

          Linear speed – tangential speed – speed

                   Merry-go-round - outside faster – inside slower

                    Rotational speed – Angular speed – RPM

                             Merry-go-round – inside/outside SAME

                   Tangential speed ~ radial distance x rotational speed

                   At center – No Tangential speed; have rotational speed

                   Away from center Tangential speed increases rotational SAME

                   Twice as far out twice the Tangential speed

(Skating at end of chain, hard to hold on to that end!!!!)

10.3 – Centripetal Force

          Towards the Center

          At right angle motion; motion circular acts to center

          Electrical force, in empty space is centripetal force

          Car around corner

          Centrifuge, Washing Machine (clothes spinning so centripetal force

 acts on clothes but does not act on water so water leaves)

10.4 – Centripetal and Centrifugal Forces

          Centrifugal – center fleeing,

when force stops object leaves in straight path (tangential)

Can on string CTrip toward center, CTrifg away form center

10.5 – Centrifugal Force in a Rotation Reference

          Which is which – frame of reference.  Stop stop and consider.

10.6 – Simulated gravity

          Spin the wheel!!! Floor of Space Station pushes towards center ie

Ctrip holding person from flying out away from center

                   Big structure turns slowly, small structure must turn fast

 


Chapter 12 – Rotational Mechanics

 

12.1 – Torque

          You turn you torque

          Torque produces rotation

          Results from leverage, longer the handle, the more the torque

          Point of contact to “hand” lever arm

          Torque  = force x lever arm

(look to component i.e. your arm not pulling straight “up” you’re not getting full torque force)

                   Nm = Joule = force x distance = unit of torque

SAME as work but very different (like degrees and degrees, sort of)

(work in direction of motion; torque to direction of motion)

          12.2 – Balanced Torques

                   Balance a seesaw; different masses – move/away pivot to get balanced

                   Triple beam Balance – slide masses, alter torque

                   Page 153; center mounted Meter Stick known mass, unknown mass

                             (Fd)ccw = (Fd)cw or  (F)ccw =  (F)cw x (d)cw / (d)ccw

12.3 – Torque and Center of Gravity

          Legs against wall, lean over and TRY to stand up (C of G beyond base)

          “kick” above or below C of G tumbling occurs/ @ C of G then no

12.4 – Rotational Inertia

          or Moment of inertia

@ rest tends to stay that way (ch 3)

          Well if rotating tends to keep doing it or if not then resists rotation

          More mass = more rotational inertia

          Long bat more rotational inertia short less

          Long legs slow gait – more rot inertia … bend leg, rot inertia lower

          Pendulum – short string faster, longer string slower

          Tight rope walk without pole …. With long, heavy pole … easier

Spinning bike wheel hard to “turn” in space (gyroscope - airplanes)

Formulas For Rotational Inertia:

Pendulum I = mr2;          Solid Cylinder = I = ½mr2

Stick about CG = I = 1/12 mr2;    Stick about End I = ⅓ mL2

Hoop about Axis I = mr2;  Hoop About ( to axis) Diameter I = ½ mr2

Solid Sphere About CG I = 2/5 mr2

Rolling

Ring vs. Solid Cylinder Same Diameter & Mass  -

Ring slower on incline plane – higher rot inertia Fig 11.15, page 158

12.5 - Rotational inertia and Gymnastics

 

Chapter 12 – Rotational Mechanics (Continued)

         

 

Bodies have 3 axis Longitudinal up/down, Median (front/back),

 and Transverse (side/side)

                   Skate around longitudinal – arms in (fast) arms out (slow - rot int higher)   

                   Dive around transverse – fold in half increase speed of rotation (rot int lower)

                   Cartwheel around Medial – legs in (rot int lower)

          12.6 – Angular Momentum

                   Gyroscopes, bike wheels, space stations

                             Faster gyro, wheel, etc higher ang mo.

                   Angular Mo = rotational inertia x rotational velocity = I x ω

                   Angular Mo = mvr – if small object & large radius (Ea orbit)

                   (CH 7.1) Linear counter part = Linear momentum = mass x velocity

                   Record spins faster – higher ang mo,

put weight on record higher ang mo @ same speed (cause rot int higher)

                   Newton’s First expressed in angular terms: obj maintain ang mo unless acted

upon by unbalanced external torque

12.7 – Conservation of Angular Momentum

          no unbalanced ext torque on rot obj – then ang mo of system is constant

          for system rot inertia x rot velocity is SAME at any time

          Skater spinning, arms out/slower = arms in/faster Iw = Iw

 


Chapter 13 – Universal Gravitation

 

13.1 – The Falling Apple

          Or the “falling” Moon through the branches

13.2 – The Falling Moon

          Falling around the Earth (even though still getting farther away 3.8cm/yr)

          Proportion of Apple vs. Moon falling vs. distance “to Earth” (center*) works

          Moon “falls” 1.4mm/s

          * - Calculus needed to show center of body ± represented CG.

13.3 – The Falling Earth

          Earth, and everything else, is “crashing” into sun

but for tangential velocities the orbs presently carry;

slow to zero ± and we slam!

13.4 – Newton’s Law of Universal gravitation

          F ~ m1 m2/d2  = mass (center) 1, mass (center) 2,

distance between two masses squared

          Increase distance decreases Force as a square of that distance

          Mass a measure of inertia; inertial mass = gravitational mass

          F = G m1 m2/d2    Where G = Universal Gravitational Constant

          For two 1kg masses, 1 meter apart G = 0.000 000 000 0667 N

                   Or –  6.67 x 10-11 N·m/kg2

          Value of G depends on units: std units mass (kg), distance (m), time (s)

          Use wrong units get wrong (numerical) answer

          The big 4 – strong and weak nuclear forces, electromagnetism, and gravity

          G between students small … student and Ea = your weight

          Mass of the Ea (get w/ G) F = (Gm1m2/d2)

Or/ 9.8N = 6.67 x 10-11N·m2/kg2 x 1kg x m1 / 6.4 x 106 m)2  

or m1 = 6 x 1024kg = Ea mass

13.5 – Gravity and Distance: The Inverse Square Law

          @ 1cm = (1 x 1) 1cm2 (apple wt = 1),

@ 2 cm = (2 x 2) 4cm2 (apples wt = 1/4),

@ 3cm = (3 x 3) 9cm2 (apple wt = 1/9),

@ 4cm = (4 x 4) 16cm2 (apple wt = 1/16), etc.

13.6 – Gravitational Fields

                   Like Magnetic Fields – strength etc but what is the “field” carried by

                   G = F/m = 9.8 N/kg = 9.8 m/s2 at Ea surface

(G higher closer to center of Ea, G lower above surface of Ea)

Arrows point TO center of Ea (closer lines are to each other G bigger)

G = F/m = G(mM/R2)/m; g = GM/R2  M = Ea mass, R = Ea radius

G = 6.67 x 10-11N·m2/kg2 ; M = 5.98 x 1024kg; R = 6.37 x 106m

 

Chapter 13 – Universal Gravitation (Continued)

 

g = 9.8 N/kg

1N = 1kg·m/s2, N/kg = m/s2

1N = force to cause 1kg to acell to 1m/s2  

Using F = ma; 1N = 1kg·m/s2 or/ N/kg = (kg·m/s2)/kg = m/s2

          13.7 – Gravitational Field Inside a Planet

                   Acceleration decreases surface to center; g decreases surface to center

                   Velocity increases surface to center; a 45 minute “ride”

                   At center Accel and g = 0 (zero)

          13.8 – Weight and Weightlessness

                   gravity produces Accel, two objects attract each other, cause Accel.

                   Pressing against Ea = weight floor pushes up against you (scale springs too)

                   In elevator – not moving regular weight; going up – greater weight;

                                      going down – lower weight; cable breaks – weightless

                   weight = force you exert on floor (elevator let’s say), see above

                   weightlessness absence of gravity =

no force from elevator floor while descending at 9.8m/s2

          13.9 – Ocean tides

                   Two-a-day opposite sides of Ea, Moon pulls on water (near);

Moon pulls on ocean floor (far) – about 1m difference in sea level

                   Moon tides too pulls like football –

Newly explained accessory bulge a result of gooeyness while

moon is in highly elliptical orbit around Ea, just after “mars”

impact (and Moon not quite “dry” yet)

                   Sun has an effect too: 180X Moon but close and far sides of Ea not

very different so no big alternate tides to see (does about ½

Moon effect); difference in pull decreases as a cube of

distance; double distance (1/8) of the tide, 3X distance (1/27)

of the tide

                   Tides must be in something big i.e. ocean; no notable tides in …

lakes, bathtubs, or you! (you're not TALL enough!!, book next

to your head – does MORE than Moon)

Line up Sun & Moon get higher highs and lower lows (Spring Tides)

Perfect = Lunar Eclipse (Ea between); Solar Eclipse (Moon between)

Sun & Moon (1st or Last quarter Phases) then lower highs and

higher lows (Neap Tides)

Tilt causes the two tides to be unequal

Not discussed land masses, tidal inertia, ocean bottom friction

                   Weird placesBay of Fundy, Nova Scotia & Alaska tides up to 15 meters

(can “see” tidal bores) Tides come in FAST

          Chapter 13 – Universal Gravitation (Continued)

 

          Moon causes high & lo Ea tides as well land goes up & down, twice

a day, by up to 25cm, EQs more are more common during

Spring Tides (Full/New Moons.)  We don’t notice land

surface ups & downs nor do ships feel the ocean raise &

lower.  When Moon formed (4.2 bya) it was very close, and

orbited VERY fast; Ea tides then about 200 feet; ideas on EQs

then?

                   Top of atmosphere, ionosphere, has ion tides too, effect living things

below .. us during weird times around Full Moons?

          13.10 – Black Holes

                   Stars would collapse (due to gravity and proximity of a great amount

of matter) if not for the burning fires (heat, from thermonuclear

fusion, expands stars.)  Collapse/Expand are balanced (Main

Sequence part of Star’s life cycle.)  But .. the fuel eventually runs

out (faster for larger stars, slower for smaller stars.)  Then

GRAVITY wins.  If star large enoughBlack Hole, the logical

extreme to having a lot of matter in a tiny volume of space.

                   If the fire gets hotter (cooler small), the star expands/contracts,

usually significantly before and at end  of Main Sequence part

of stars cycle.  Hydrogen to Helium fuses to Carbon. Expands,

to Mars becoming a Red Giant; when Helium all used up the Red

Giant will collapse to a Black Dwarf.  Then we “wait” for a

Super Nova in the neighborhood to push us into something

else and look for a new start.

                   If the star is massive enough (2-3X our Sun) the process occurs as

above BUT the collapse also crushes the atoms, leaving NO

space in between, collapse continues until density = ∞,

nothing, even light (hence BLACK hole), escapes.  Black

Hole has same mass as previous star but has an enormous

gravitational field, don’t venture into the Event Horizon of

this thing that can’t be seen … the collapse of Space Time

itself.  The classic Funnel spaced space; ending at a Singularity.

                   See” Black Holes when the situation is right; binary star that orbits

around nothing, usually very fast.  “Look” for X-rays the last

gasp of matter just before it is dragged into nothingness. 

Black Holes “rove” eating unendingly until nothing remains;

                     then they rove some more.

 

 

 

Chapter 13 – Universal Gravitation (Continued)

 

13.11 – Universal Gravitation

          Spheres tell us gravity works; so many spheres out there –

gravity universal.  No square planets –  noted so far anyway

          Planets “attract” each other, cause perturbations in orbits

          Perturbations result in finding “new” planets – math guys tell the

scope guys where to look … there it is!

                   Big Bang …Big Crunch.

Will Gravity eventually win (open or closed Universe(s)) 

          F = G m1m2/d2 = governs the Universe and everything in it

          Newton started a revolution – the best of everything/everyone

          Science, art, writing blossomed

 


 Unit 3 - Heat

 

Chapter 21 – Temperature, Heat, and Expansion

 

Warmer – Higher KE

          Warm penny by hitting it w/ hammer

          Flame to liquid – Liquid gets warmer

          Compress air fast – gets warmer

          Move atoms faster – gets warmer – has more KE

          Warm by fire your KE is increased

 

21.1 – Temperature

          How hot or cold is it? – temperature

          Hotter bigger expands, colder smaller contracts

          Mercury, hotter, bigger, VERY predictable (coefficient of expansion) –

thermometer, wow!

                   Celsius (-273 – to), Fahrenheit (−459.67 – to) Kelvin (0 – to)

 

          Temperature and Kinetic Energy

                   Random motion of molecules are temperature

                   Temperature ~ Average KE of molecular translational motion

                             Motion that is linear or curved.

                   2 Gallons of boiling H2O has twice the total KE as 1 gallon of boiling H2O

                             Temp the same as both groups of molecules have the same Average KE

21.2 – Heat

          Hotter TO colder (see again Chapter 24 Thermodynamics)

          Hot stove, heat TO you

          Ice, heat from you

          Heat is energy transferred from one object to another

          Energy can be transferred many different ways; among them heat, work, etc

Object has energy; can give or accept heat (depends on which is hotter)

                   Object does NOT have heat

          The energy of heat was “thermal” energy (Chapter 8) from now on it’s

“internal” energy

          Object has energy to DO work; it does not “have” work

21.3 – Thermal Equilibrium

          Hot next cold, eventually become the same

                   Aquariums with hot & cold containers in medium water;

all 3 become the same temperature

                             Hot glass – to room temp (heats room a bit); Thermometer

 

Chapter 21 – Temperature, Heat, and Expansion (Continued)

 

gets heated/cools the water, heats cool the air

21.4 – Internal Energy

          =  translational KE + rot KE of molecules + KE from internal

movement of atoms in molecules (can be expressed as heat or work)

                   Can “heat up” because molecules jostled faster …

                   Phase change – can result in intake/output of energy & no temp change

21.5 – Measurement of Heat

          “See” heat energy by monitoring temperature (transfer of energy from

substance to expanding/contracting material in “thermometer”)

                   Looking for reproducibility (precision) in energy transfer measurements

                   So, for a standard, use something that behaves the same everywhere – water

                   Pure H2O … a calorie = amount of energy (heat) to raise 1gm of H2O 1°C

                   Boil & distill it and everyone can get pure H2O, anywhere

                   Water is a lot of 1’s; Specific Gravity = 1; Specific Heat = 1; Density = 1; etc

                   Kilocalorie = 1 000 calories (1kg of H2O 1°C)

                   1 food Calorie = 1 energy kilocalorie = 1 000 energy calories

                   Calorie & calorie are energy, SI unit of (all) energy joule

                             1 calorie = 4.184 J; so 4.184J raises water temp by 1°C

                   How Calories determined in food we eat?  Burn it! 

Measure rise in temperature of water atop “the fire”; easy to do.

                   Peanut or gasoline; Calories or calories easy to determine

21.6 – Specific Heat Capacity

          Things cool/heat at different rates when exposed to the same

output/input energies

                   Onions, squash, pie filling (lots of water) long time to cool to eat

                   Mashed potatoes, pie crust (less water) can be eaten sooner

                   Can heat metals (Iron 2 min, Silver 1 min) to 100°C much faster than a

like mass of H2O (15 minutes)

                   Some materials absorb heat, molecules move faster, temp up (exothermic)

                   Others materials absorb energy (heat) and cool (endothermic)

                   Some of the absorbed energy, in either case, goes to heating but not all

                   Water 1 calorie/degree; Iron 1/8 calorie/degree

                   Water – soaks up energy in rot of molecules, internal vibs, & bond stretching

                   Iron – lattice bound – just requires back-forth shaking of molecules

                   WATER HIGHER Specific Heat (Capacity) than Iron

                   Specific Heat of something = energy (heat) required to raise temp 1°C

                   Lots of stuff has LOWER Specific Heat than Water; water IS weird (is 1)

                   Q = mcΔT Q = amount of heat (calories), m = mass (g), T = temperature (°C)

 

Chapter 21 – Temperature, Heat, and Expansion (Continued)

 

calories to Joules = calories x 4.184J/calorie = Joules

21.7 – The High Specific heat Capacity of Water

          Water can absorb a lot of energy (heat) and exhibit very little temp change

          Water good for cooling, engines, other water (in heat exchangers)

          If coolant temperature rises to that of “the engineno more cooling happens

          Water cools slowly good or bad (solar heating, trombe walls, gas engines)

          Good for Europe/ Canada, ocean keeps higher latitude countries “warmer” in

winter “cooler” in summer Atlantic current (Gulf Stream) brings

“heated” water up from Caribbean (equator) and east by the “westerly”

winds; water temp ± same year round moderates air temps for the better

San Francisco – nice; Buffalo & Washington DC – not so nice

Center of continents – great hi’s and lo’s – not so nice (we … don’t

have seasons … sort of

21.8 – Thermal Expansion

          Energy changes (heats/cools) molecules jiggle at different speeds;

get bigger/smaller, longer/shorter

                   Concrete cracks (“curing lines” installed to control cracking

location)

                   Railroad tracks, bridges must be designed to allow for expansion/contraction

or trains derail and bridges get stuck up/down

                   Get metal jar top off glass jar;

put metal top under hot water;

it expands faster (good thermal conductor)

than glass (good thermal insulator) jar – opens! Magic … right …

                   Bimetallic Strip – two metalstwo coefs of expansion – coil bigger/smaller

                             Should be able to use that (about a thousand different ways)

                             How about a thermostat?????

                             Heat gas, out of the tank it comes!?!

21.9 – Expansion of Water

          Weird … @ freezing point 0°C (32°F) Water contracts; everything

else … expands; water SMALLEST at ~ 4°C, expands in

BOTH directions up and down (@ 0°C 1.0002, @ 4°C

1.0000, @ 8°C 1.0002) again; blame it on the weird crystal

structure of water, open structure when solid, makes up more

space in becoming a solid

                   Ice over water in pond, happy fish – let’s go ice fishing … w/ your

Lincoln Navigator …

 


Chapter 22 – Heat Transfer

 

22.1 – Conduction

          DIRECT CONTACT

Heat end of metal rod; you get burned at other end of rod

          Pt, Au, Ag, Cu, Al, Fe – Good conductors (heat, electricity, e-)

          e- Flow freely, the critical thing

          Atoms/Molecules collide – faster they = hotter

          Hand on metal and wood same room – which cooler?

          Poor conductor = Insulator

                    Plastic, Styrofoam (hot cocoa), wool* (good sweater), fur*,

feathers*, snowflakes*, straw, paper, cork

(* - porous - trap lots of air)

Snow around a long time, good reflector (optics), till it gets dirty

                    Most Liquids (Mercury – NOT) and Gasses (Air good insulator)

          Heat = energy; cold = absence of heat; heat is real – cold is no energy

                   Keep the heat in; not the cold out

          Heat is unstoppable – can slow it down …Olber’s Paradox

                   Insulation DELAYS transfer

22.2 – Convection

          Warmer-upper

          Hot at top, stays at top; hot at bottom – moves to top

                   Displaces cooler whatever and down it goes to get heated

                             Convection cell; the universe at work

          All fluids (liquids & gasses); pan on stove, plate tectonics, air in room

                    Heat expands, become less dense and of course rise.

                    Cool contracts, becomes denser and of course sinks

                   Buoyancy – works “Titanic” air mass

                   Bet heating vents in ceiling; how’s hot it get to floor?

          Wind – weather – UP the mountains .. cools because, up there, less

pressure, air gets bigger, fewer collisions, cools, comes back down

post-collision collisions smaller, less energetic (less energy), less

heat, cooler …

22.3 – Radiation

          Energy from sun to Ea, not by conduction (air is a bad conductor),

not by convection (hot on top) although convection happens at

surface when we’re hot at the surface (does not so high up as the

top of the atmosphere)

          Radiant Energy (radiation) transmitted through a VACUUM, now

that’s neat, and necessary, or we’d be frozen

 

Chapter 22 – Heat Transfer (Continued)

 

                   Camp fire – that’s the heat (energy) you feel, electromagnetic

(energy) waves; include radio, microwave, infrared, visible,

UV, X rays, gamma rays (long to short wavelength)

Act also as particles – but not proven – at SAME time

                   Everything emits ALL the time – motion detectors – Geiger counters – etc

                             Low temp (energy) long λ; hi temp (energy) short λ us between

radio and visible IR range penetrates, absorbed by, skin – burns

                   Fireplace too hot for eyeballs put on your dark (any proper UV blocking)

glasses

22.4 – Absorption of Radiant Energy

          Reflections opposite poor absorbers (mirror – most to almost all back)

          Good absorber – dark; best black (best reflector white)

          White box – close, one hole – looks black inside, light in multiple

reflections, does find its way out (windows, doors from a

distance, the same)

                   Black car windows closed …

22.5 – Emission of Radiant Energy

          Good absorber, you emit (usually a different λ); black object cools

          Poor absorbers, you don’t or don’t emit much

          Black pot cools faster than white or mirrored one

          Black pot warms faster than white or mirrored one

          Solar panels dark not white not “reflective” (any more than needed)

          Stand in/out of shade.  Do that w/ black/white coat …

22.6 – Newton’s Law of Cooling

Objects eventually come to equal temp to surroundings

          rate of heating/cooling to get there depends on temp

difference wide range works up/down fast then slows as gets

nearer surrounding temp

Rate of cooling (by conduction, convection, or radiation) ~ ΔT

ALSO for heating. Drop you in boiling oil vs. a little over room temp

          You heat up fast/slow

22.7 – Global Warming and the Greenhouse Effect

          A car again (or greenhouse) – model of greenhouse effect

          Short waves in through glass – reradiates long waves off car interior but

those waves can’t get back out so car interior heats up ‘cause more

energy (heat) added to closed system, therefore  more “terrestrial

radiation”

No dogs/kids in car!!

 

Chapter 22 – Heat Transfer (Continued)

 

500K yrs 19 - 27°C (now 27°C …) CO2 “the” g-house gas

Solar input = terrestrial radiation emitted by Ea; result or temp Ea

Mess this up, burn fossil fuel (for a little while longer) absorption/emission

changes temp up ice caps (good reflectors so keep us cool) shrink,

we absorb more and more energy we get hotter and hotter we get

extinct ….

“Can’t just change one thing” … less rain, less food, less people; it’s your planet to inherit … I’ll be dead.


Chapter 23 – Change of Phase

 

23.1 – Evaporation

          Where’d the water go? Liquid to gas. 

          Temperature = average KE of molecules = collisions

          Some gain more/some lose KE; it the process; gainers leave as vapor;

eventually all gone (billiard ball physics) Still got conservation -

                             Air above cools … humidifier

                   You sweat/glow to cool off, dog tongue, Stegosaurus plates – get rid of heat

                   Can’t sweat, better be able to swim.

23.2 – Condensation

          Opposite of evaporation – gas to liquid

          Water collects on the outside of a cool … glass, can, window, mirror

          Gas atoms/molecules collide with cold surface .. lose energy (KE, heat)

get stuck to surface, not enough to “leave”

                   Air warms … dehumidifier …

 

          Condensation in the Atmosphere

                   Temperature determines amount of water (humidity) air can hold

                             Not 100%’s are created equal; hotter 100%’s carry more water

than colder 100%’s; Humidity is relative … it’s 100% for the

temperature of the air.

                   100% not measure of the amount of vapor but the amount of vapor

that is possible to be held at whatever the temperature is

                   Air saturated, air cools, vapor converts to water … fog, dew, mist

                   Less fog etc if windy; no wind amazing fog banks …

 

          Fog and Clouds

                   Air warms at Ea surface, goes up, cools, condenses, falls, cycle

                   Got dirt (acid) particles; got rain (acid)

                   Day land colder the hotter than cooler that temp stable bodies of water

                   Oceans more temperature stable than lakes than rivers, steams, creeks etc

                   Particle size – terminal velocity – bigger/faster – falls as rain

                                                                       smaller/slower stays up fog

23.3 – Evaporation and Condensation Rates

          leave shower to towel off – cools fast outside; evaporation cools you off

          towel off in shower  - stay warmer

          if evap and condensation rates the same – “looks like” nothing happening

          rates = “equilibrium” balance both normally happen same time

 

 

Chapter 23 – Change of Phase (Continued)

 

23.4 – Boiling

          Where Evap happens at the liquids surface; boiling happens below

surface; bubbles (gas) forms inside water (bottom or pot)

buoys to the surface and is gone.

                   Bubble pressure needs to be greater than surrounding water pressure

duh to form bubbles and rise through rest of non-boiling water

                   Water boils at less than 100°C @ higher elevations [altitudes]

(less atmospheric pressure, higher in the air column,

mile higher, water boils @ 95°C)

                   Want to boil water/cook food faster … use a pressure cooker; as

water nears boiling pressure of air inside cooker raises

prevents boiling heat continues up, still no boiling but higher

temperature cooks that food faster

23.5 – Freezing

          Remove heat – particles slow down; “attracted” together, fuse

          Vibrate “fixed” positions – frozen a solid is born.

          Depressed “freezing point” water, put sugar, salt, alcohol (Titanic

survivors) etc in it.  They get in the way no more good

vibration – till lower temperature

23.6 – Boiling and Freezing at the Same Time

          Huh? – Water @ room temp … but in a vcuum boils, takes heat

from remaining water … eventually water cools to … freezing

does both @ same time

                   Frozen bubbles of boiling water – hope to see that!

23.7 – Regelation

          Crush ice with pressure, knife, hammer, weight placed on top –

                   Doesn’t thaw (i.e. heat) but melts @ temp lower than freezing (0°C)

                    Piano wire masses suspended on ice block, slowly goes through –

w/out going above freezing point …

Ice skates do the same thing – blade pressure ice melts in front

freezes behind – all below freezing point!

Double std Atmospheric pressure – depress melting occurs @ 0.007°C

          Not real depressed but depressed none-the-less

          Remove applied pressure – freezes right now - @ lower than 0°C (regelation)

                   Water is weird AGAIN

23.8 – Energy and Changes of Phase

          Enough energy (heat) everything melts, more energy (heat) vaporizes to gas

          Take energy (heat) away – reverse of above occurs

 

Chapter 23 – Change of Phase (Continued)

 

          There are “steps” continually add/remove heat temp won’t change …

phase will, that change requires heat (energy) too.

                   Any ice remains – no change in temperature will occur until ALL melted

                   ½ calorie/degree; but about 80 calories to complete phase change (1gm ice)

                   1 calorie/degree 0°C - 100°C then temp stops again, energy still applied

                             continuously, need 540 calories to make the (for 1 gm) jump to

boiling!!!

                             A watched pot never boils … for a long time anyway; wow now that’s

HIGH Specific Heat for you

                   See figure 23.13, pg 348, “see” the steps … and risers; water is … weird

                   ALL of works, just the same way, in reverse – 540, 100, 80, ½ etc …

                             That's a lot of energy return(ed)

Water hotter than 80°C will freeze FASTER than water @ 60°C

(more evaporation and energy loss [540 calories/gm] occurs

@ higher temp so less water left to freeze …)

                   Refrigerator – liquid comes into refer from cool coils, turns to vapor (as

heat from inside refer goes into the liquid – making a vapor – and

the energy (heat) to make the vapor is then REMOVED from refer

by going through compressor, then pumped outside vapor cools to

liquid while going through coils outside, on the back, of the refer;

this cycle repeats itself removing more heat from inside and making

the area outside the refer warmer . AC same thing put hot air outside!

In the mood to check an Iron’s temp; do it with a WET finger – all the

energy needed to vaporize the water on your finger will save you from

a burnt finger (do not touch too long.)

Blow air over ice, air gets cooler, loses energy melting ice, so air cools (ice

disappears eventually.)

Stick your hand in the oven; for a short period of time; it takes time to

transfer that 450°F (usually) to your hand/arm BE CAREFUL

Firewalkers BE CAREFUL; wood bad conductor even if HOT, no time to

                             dawdle!
Chapter 24 - Thermodynamics

                    (see Chapter 21.2 Heat)

          Study of heat; transformation of heat into mechanical energy; movement

of heat; conservation of energy; hot TO cold

 

24.1 – Absolute Zero

          Atoms/molecules go faster – gets hotter – collisions more frequent

bounce farther apart (on us, ouch!)

                   How about go slower – forever? – no absolute, defined limit,

Absolute ZERO; NO energy (heat) is left to extract. -273°C

                   Gasses contract 1/273rd /°C so @ -273 (-459.69°F) we’re done, no

pressure, consider that.  No pressure means no collisions, means no

motion; matter STOPS … consider that!

                   Absolute Zero = 0°K by definition

                   He boils @ 0°K … Kelvin is the scale of choice, stars, light (temperatures) etc.)

          24.2 – First Law of Thermodynamics

                   Add heat to system – “transforms” to = amount of some other form

of energy (thermal version of Conservation of Energy, Ch 8.6)

                   OR – Energy cannot be created or destroyed – it just moves around,

or “converts” around from place to place

Heat added = increase in internal energy + external work done “by” system

                   Must define “system” – must know what’s in/out of system

                   Steam Engine …. Moves train … makes lots of excess heat … inefficient

                    Closed can on stove … heat … gets hotter pressure inside increases

(very dangerous!!!) … does no work.  If actually did work …

internal energy less … temp would increase less and other “work” 

would be done …

                   No heat added – internal energy can still increase if you compress it

(increase in “potential energy” like a spring, wants to “unsquish”)

                   Expand w/out adding heat – reduce the internal energy of system

                   Tire pump mechanical to thermal …

          24.3 – Adiabatic Processes

                   Expansion/contraction of a system w/ NO gain/loss of heat

                   Bike pump – pump fast no time for energy transfer

                   Car engine – explosions in 1/100’s of a second – energy goes to

moving car, not (just) heating engine.

                   Change temp of gas ~ change in pressure

                   Large air masses go up temp/pressure down – go down temp/press up

                             Cools/heats 10°C/km

                   Chinook - cold/dense airs flows down, from Rockies – compresses/warms –

 

Chapter 24 – Thermodynamics (Continued)

 

Denver” gets a bit warmer during the winter

Airplane – if took outside -35°C air – compressed to sea level pressure,

would be 55°C (131°F) and  thus have to be cooled @ altitude …

cabin “Altitude Pressure” held @ 12,000’ (± 3km) so you get 30°C

back for about 80-85°F; still need the AC.  How ‘bout you start w/ air

at the temp/pressure where you are; then climb to 12,000’, close the

air “bleed” valves,  and then see (bet you'll need a heater.)

          24.4 – Second Law of Thermodynamics

                   Heat “flows” from hot to cold; hot brick TO cold brick (can be

forced the other way – won’t flow by itself though)

                   From inside your warm house TO colder outside in winter

                   From warmer outside in summer TO inside your cool house

                             Stop the “transfer” house warmer/cooler (triple pane windows)

                    Ocean nice and warm – just why can’t get energy out of it (without

external energy input to make that heat flow “backwards”

          24.5 – Heat Engines and the Second Law

                   Converts internal energy to mechanical work

                   ALL Work to heat easy – energy to overcome friction – and you’re off

                             (rub hands together, push box on floor)

                   ALL Heat to work – no go – some heat to mechanical energy (generally

NOT much), to then to something (steam engine 1700, cars)

                   Heat engine absorbs heat from hotter reservoir (cylinders), converts

some heat to mechanical work (drive train – wheels), and

expels (exhausts) heat to lower temperature reservoir (the

atmosphere outside the exhaust pipe.)

                   Thot x 0.???? (less than 1 ‘cause less than 100%) = some Work + Tcold

                   ALWAYS exhaust, so always less than 100% efficient, always waste,

always thermal pollution (ok on  a cold day, not “so hot” on a

hot day)

                   Efficiency … Carnot Efficiency … (1824) … = Thot - Tcold / Thot; want

NO difference in input vs. output temperatures, best of luck,

heard of friction?, how many sources of friction do you think are

in a “simple” car engine?

                   T = °K

                   Sample 400°K – 300°K /400°K = ¼ = 25% efficient, that’s pretty …. Good

                   Steam is used a lot (lots of energy to heat … find a natural source of heat

                             …Thermal Field (around a volcano), nuclear … ) to turn stuff,

piston, turbine, etc, to make mechanical work – Alameda Power &

 

Chapter 24 – Thermodynamics (Continued)

 

Telecom – The Geysers

                   Turbo Charger – increases pressure in engine, more air to burn with gas –

intercooler helps to decrease wasted heat … returns cooler “exhaust”

to engine … from exhaust (ironic.)

                   No Ideal Engine – pesky friction again but there are additional limitations

with 2nd Law

          24.6 – Order Tends to Disorder

                   Energy not created nor destroyed (1st) and some energy is wasted in

transformations (2nd)

                   OR order degenerates into disorder (chaos)

                   Potential Energy of gas tends towards chaos as it is “utilized” very

                             inefficiently …

                   Electrical systems … to random, useless, heat

                   Each transformation increases chaos

                   Take a chaotic system, it will NOT become more orderly ever

                   2nd law ======= Universe tends towards ever greater disorder

                   Open the jar atoms/molecules come out; out does not rush in …

          24.7 – Entropy

                   Order TO Disorder

                   ΔS = ΔQ/T (where S = Entropy, Q = amount of heat added to a

system, and T = temperature)

                   Entropy (disorder) increases; ability to do work decreases; the

natural order

                   If there is energy input, living systems, entropy DECREASES until

the “end” when the system begins the slippery slope to

eventual system failure; old age, decomposition … overall

entropy of the greater system is still INCREASING. 

There are little “islands” of increasing organization in an “ocean” of

decreasing organization. 

Does human thought defy entropy; become MORE organized with

          time and with the refinement of ideas and concepts?

Perhaps much of THIS depends on you and what you do with what

you learn in this class!!  Defy Entropy!

                   Entropy IS probability; anything CAN happen even if the likelihood

of the event occurring is astronomically small.  It’s this

astronomical smallness that sometimes makes us believe some

things are impossible.

 


Unit 5 – Electricity and Magnetism

          Chapters 32 – 37 must be understood to be building blocks, one upon

the other.  Do not go too fast; do not not get it and, try, to go on. 

Get it and it will stick with you.

 

Chapter 32 – Electrostatics

         

32.1 – Electrical Forces and Charges

          Electricity @ rest

          Gravity, attraction to things with mass; your weight on Ea or

                   wherever.  Electrical force is billions of times stronger (but

has a very small area of effectiveness) than gravity.

                   Electrical attraction and repulsion are = opposite forces acting on

lots of stuff most all the time.

                   We have atoms/molecules all around us, they have +’s and –‘s and so

we are exposed to these electrical forces from/to everywhere

                   Bohr atomic Model - +’s/-‘s built into the model; protons (+),

electrons (-), and neutrons (zero)

Proton are 2,000x the mass of an electron (actually 1860x), neutrons are

slightly more massive than protons; most atoms have = #’s of

Proton and electrons and thus usually carry no charge).  Ions and

isotopes are exceptions

                   Like charges repel; opposite charges attract

                   Protons/electrons held in nucleus/shells (very close to other protons/electrons)

by Strong nuclear forces (Ch 39); electrons “orbit” nuclei, not like

planets, but according to trhe physics of the very small Quantum

Physics (Ch 38.)

                   Pith Balls – attract/repel, same … with people

          32.2 – Conservation of Charge

                   Proton +; Electrons – (e-)

                   Atoms generally NEUTRAL, no net charge, = # of Protons & Electrons

Lose a Proton(?) atom becomes (net -)

                   Gain an Electron atom becomes (net -)

Lose an Electron atoms becomes (net +)

                   Atom w/ charge = Ion (+,-,+2,-2, etc)

                   Positive Ion = lost one or more e-

                   Negative Ion = gained one or more e-

                   If atom is an Ion, you have an electric charge

(you can act like a magnet, form bonds, do stuff)

                   Inner e- strongly held … outer e- more loosely so

 

Chapter 32 – Electrostatics (Continued)

 

 (called valence e-‘s – they can be collected, given away, or shared)

                   Rubber holds e- well, fur not so; if rubber rod rubbed on fur e- transfer to

rubber and a net – charge develops on the rubber rod, + charge on

the fur.

                   Silk holds e- well, glass or plastic not so; if silk rubbed on glass or plastic

rod e- transfer to silk and a net – charge develops on the silk, +

charge on the glass or plastic rod

                   Because e- just move around, not created or destroyed, they – there

“charge, is conserved”

                   This conservation – like energy & momentum is very important – we

are talking e, we are talking about whole proper numbers

(no fractions)

          32.3 – Coulomb’s Law

                   Newton’s law of Gravitation:

F = G(m1m2/d2); m = mass, d = distance, & G = gravitational constant (

                   Well Electrical force is also inversely proportional to distance between

two things w/ charges so:

F = k(q1q2/d2); q = quantity of charge, d = distance between

charges, & k = is a proportional constant (9,000,000,000N·m2/C2)

a very BIG number compared to “G”

                   Charge measured in Coulombs; 1C = charge of 6.24 x 1018 e- (a lot of e-)

                             About a 100w bulb in 1 second

                   Two 1C charges 1m apart = 9.0 x 109N (that’s 10 battleships! & RARE)

For gravitational attraction:

Two 1kg masses 1m apart = 6.67 x 10-11N (a small amount of … force)

          To get 1N (just 1) masses would have to be122,000kg … that’s big!

Summary:

          G – small, k – large, Fgrav = attractive only, Fcharge = attract or repel,

                   Both are inversely–squared proportional relationships

Because things even out there is no measurable electrical force between

Ea and the Moon

                   An e- in one atom can get closer to the nuclei of another atoms than their

own e- thus the origin of bonding by loss, gain, or sharing of e-

          32.4 – Conductors and Insulators

                   Ability to pass or hold on to e- makes a good conductor or insulator

                   Conductors:

Metals good (heat & electricity) because their e- are loose

                   Insulators:

 

Chapter 32 – Electrostatics (Continued)

 

Rubber/Glass bad (heat & electricity) have tightly bound e-

                   The BEST conductors are the WORST Insulators &

                   The WORST conductors are the BEST Insulators

                   Hi-voltage transmission lines are good … ???  Tightropes?

                   Germanium/silicon are SPECIAL … insulators, good ones until

                             You add an impurity, say 1 in 10,000,000 atoms and it insulates

sometimes/conducts sometimes, it “semi-conducts”;

hello Si valley, Intel, AMD, and on and on and on

                   Semiconductors are transistors (on/off switches, 0 &1 switches)

                   Insulators, semiconductors, conductors, & SUPERconductors!!!!

                   Some metals, near 0°K, have NO resistance (∞ conductivity)

so e- REALLY FLOW

                   Since 1987 “hi temp” (100°K) superconductors have been getting a lot

of attention; these hi temps are easier to get to and maintain       

          32.5 – Charging by Friction and Contact

                   Airplanes flying in air, pick up static electricity; no problem … try to

fill the gas tank, static, like lightening, produces sparks, humm sparks … gas … NOT airplanes also come with static dissipaters

(strings attached to the trailing edges of wings and things.)  So

when you land and fill up you won’t blow up; by the way there is

also a wire from the gas pump that is attached to metal on the

airplane to catch whatever the dissipaters don’t manage to get

walk a carpeted room, play zap the sibling, touch the doorknob, pull dry

laundry apart in a dark room – sparks, sparks, sparks

          32.6 – Charging by Induction

                   Bring charge “into the neighborhood” (don’t even have to touch) the

charge will cross over and charge the neutral object – inducing it

to have an electric charge

                   Charge can be dissipated through grounding

                   Lightning, up not down; clouds (-), “ground” (+); potential gets to be

large enough, boom – lightning goes to REATEST potential – the

 sharpest point, very little area – lots of potential, especially if a

good conductors attaches it to THE groung (lightning rods, are

you one, for good ideas …) Ben Franklin was smart … and

LUCKY … and very smart

          32.7 – Charge Polarization

                   Figure 32.11, page 512; if there are not electrons to flow, they still

move towards/away to/from charges brought near (the electrons

 

Chapter 32 – Electrostatics (Continued)

 

… move away/to within the atom) the atoms becomes polarized

 (+) on one side (-) on the other; the atoms become a zillion little

magnets – working together sometimes

                   Balloon, rub on head (hair), pick up electrons, get (-), attract … wall

lets say, so glue a balloon to the wall, paper to a hair comb

(see figure 32.12 &32.13)

                   Water, “Mickey Mouse”, is a great dipole molecule (magnet); that’s

how water “goes up inside wood, walls, etc – it’s pulled up,

attracted up, it’s magnetic

 


Chapter 33 – Electric Poles and Potential

         

33.1 – Electric Fields

          Field around mass = gravitational force field

          Something might not be in direct “physical” contact but can be in

contact with the (gravitational, magnetic, or electrical) “field”

around the thing or things

                   Gravity holds planets around sun, electricity holds electrons around

protons

                   Electrical fields have magnitude and direction (resolve with vectors)

                   + field = away form center

- field = towards center

          33.2 – Electric Field Lines

                   + field = away form center (by convention)

- field = towards center (by convention)

                   Closer the lines = more intense field; farther apart = weaker field

                   Point (towards/away), pair from (+) to (-), parallel sources equals lines

from (+) to (-)

                   Overhead and magnets …

                   Can get very complex, non-equal – moving charges …

          33.3 – Electric Shielding

                   The insides, spheres, cubes, “shielded” cables trend to distribute external

charges and cancel them out, thus inside there is NO charge, you’re

protected by the canceling effect – lightning while you in the

(negatively grounded) car; NOT on the phone, under a tree,

standing tall in a field,  or taking a shower (you’re at the “end” of

those two lines.)

          33.4 – Electric Potential Energy

                   Work requires movement, from a force; going up increases Grav Pot Energy

                   Same effect electrically, you increase Elect Pot Energy, “drop” and it’s

attracted to the other (opposite polarity) object

                   Gravity and Electricity work essentially the same way, more lines of force …

          33.5 – Electric Potential

                   Like the speed of the “water” in the pipe; fast = higher voltage

Double the number of charges doubles (triples - triples, etc) the work

that can be done “increase the potential” for work

                   Electric Potential = volts = Electric Potential Energy/Charge

1 volt = 1(joule/coulomb)

Electric Potential energy can be tiny but charge is way tinnier so EP (in v)

can look huge even when both guy on right side of equation are

 

Chapter 33 – Electric Poles and Potential (Continued)

 

very tiny (EPE) and very very tiny (charge)

An electrical potential of 1 volt = 1 joule of energy/ coulomb of charge

                   1,000 v = 1,000 joules of energy/1 coulomb of charge

                   Balloon rubbed in hair, feet across carpet, planes flying can pick up

thousands of volts of potential (spark) but very little charge goes

with the balloon (a millionth of a coulomb, a thousandth of a joule

perhaps … plenty to destroy a computer mother board or other

integrated circuit board with microchip – ground yourself before

touching such fragile equipment)

          33.6 – Electric Energy Storage

                    Capacitors are very dangerous – you can die touching a charged

capacitor ( old TVs, new components, anything that needs big

volts to fire up.

                   Thin foils – paper in between – pump energy into foils (plates),

discharges when plates are connected together (two wire out the

bottom, usually); hold charge for a long time; TV off for a long

time, still, watch out, the work to charge those foils (plates) is

waiting to be discharged.  To be safe discharged the capacitor by

connecting the wires to a safe path of discharge.  Don’t over

charge – will heat and go boom.  Energy stored in the electric

field inside capacitor coil. 

                   There is energy IN them there fields (how suns energy gets here through

nothing …

          33.7 – The Van de Graaff Generator

                   Electrons shed from rubber belt, that picks up excess electrons from

unit base and deposits them onto a hollow metal sphere (electric

field inside sphere is ZERO) builds up thousands of volts in

potential static electricity to be discharged by sparks to a positive

(grounded) object; student, ground probe, etc.  As student holds

on hair picks up charge causing hairs to repel each other. 

                   Sharp point can’t hold much charge, discharges easily so not much shock;

sphere holds charge well; bigger the sphere the higher the discharge

voltage … 1m diameter sphere = 3 x 106 v, discharge @ 3 x 106 V/m.

                   Up to 20 x 106 v in chamber w/ hi-pressure gas.

 


Chapter 34 – Electric Current

         

34.1 – Flow of Charge

                    Need potential difference to get charge to “flow” (pressure in “the pipe”)

                   Flow will occur if there is “potential difference or voltage” (tilt the pipe)

                   One end of wire in receptacle the other in your hand … don’t do this …

while your standing in a nicely “grounded” puddle of water …

DON’T do that … lots of potential difference, voltasge through you

(your nerves, heart, brain – all your “electrical parts – may shut them

off – NOT a good idea …)

                   To keep flow (voltage) going you must sustain the difference Like water

flow over a falls – you need a reservoir of “difference” or the system

… levels out and stops – you need a voltage … pump

34.2 – Electric Current

          Flooooow of electric charge (electrons)

          Electrons moving freely “conduction electrons”

          Current = Amperes aka Amps …

          Amount of current controlled by size “gauge” of wire #10 = 30 amps,

#12 = 20 amps, #14 = 15 amps; gauge like shoot size in

counter-intuitive - bigger # = smaller diameter wire

1A = 1 coulomb of charge/second

                   1 coulomb = charge of 6.24 x 1018 electrons

                   5A “load” requires 5 x (6.24 x 1018) electrons to pass any point in the

wire cross-section (hope the wire is not frayed or damaged); if

the wire is too small, it gets hot, it maybe starts a fire; not

uncommon when the protection for the wire, fuse or circuit

breaker is too small (“it kept popping the fuse”); my home

burned down – insurance likely voided by misuse of electrical

wiring … big loss

                   Current passes … otherwise it does nothing to the wire

                   The wire is like a pipe; the larger the diameter the more “water” it can carry

          34.3 – Voltage Sources

                   Source of potential difference

                   Batteries, generators, car alternators that convert chemical/mechanical

energy to electricity are “electric pumps”

                   Source voltage is called electromotive force (emf); the voltage provides

“electric pressure” to move current.

                   AP&T, PG&E use BIG generators (nuclear, dams, turbines, wind, solar)

                   120J of energy/coulomb of charge flowing in the circuit

                   Charge flows, water flows; voltage/pressure do not “flow”

 

Chapter 34 – Electric Current (Continued)

 

34.4 – Electric Resistance

                   Source of “impedance” for the flow of current; dirty wire ends can get

very hot (Al wire vs. Cu …)

                   Big wire (pipe) offers less resistance than a small one

                   High temp = high resistance … Carbon opposite hi temp lowers

resistance (loosens the electrons, move easier)

                   Resistance = ohms

          34.5 – Ohm’s Law

                   current = voltage/resistance

                   1A = 1v/Ω (ohms up – current down – heat up)

                   I like v = IR

                   1v = 1A/1Ω

          34.6 – Ohm’s Law and Electric Shock

                   Current or voltage, which is scarier?

                   A little current can hurt or kill you; voltage, not big deal, IF not

accompanied by any significant amount of current (recall Van de

Graff Generator loads of volts, almost NO amps)

Table 34.1, page 537

                   You will feel the power if you stick your finger in a wall plug (don’t do

that); you will feel “it” less in rubber souls shoes, more in bare

feet, and  maybe dead if in a puddle of water (grounding

 

                   Birds on “a” wire ok …. Squirrel on two wires boom

          34.7 – Direct Current and Alternating Current

                   DC one direction; AC back & forth but basically nowhere

                   AC 60Hz, cycles/second of back & forth

                   Phase “A” + at same Phase “B” -, charge is flowing …

          34.8 – Converting AC to DC

                   Got diode? A check valve for electrical circuits, allows flow in only

ONE direction AC becomes …. DC

                   Capacitors smooth pulse, charged bumpy; discharge smooth and DC

          34.9 – The Speed of Electrons in a Circuit

                   Flip switch, light goes on, electrons don’t go anywhere but the signal

ON in transmitted by the electric field generated by the circuit;

the wire is the guide to correct fixture, collisions among electrons

are common, wires heat up

                   In a DC circuit electrons actually move about 0.01cm/s or take about 3

hours to go one meter

 

Chapter 34 – Electric Current (Continued)

 

In an AC circuit electrons don’t anywhere, they hum, producing noise,

motors produce a ton of noise, which needs to be dampened or

shielded from sensitive equipment

                   Your voice “caries” on the electrons of the phone wires (@ the speed of

light); so say something … important!

          34.10 – The Source of Electrons in a Circuit

                   Electrons are built into the conductor, the wire, can’t buy an empty,

electronless wire …

                   Turn on the “juice” electrons vibrate, with the generated field, and

make the light light up. Filament vibrates and heats up, then

luminance's to make itself bright.

          34.11 – Electric Power

                   Electricity production expends energy; this energy produces heat – a

bad byproduct to electrical usage

                   The rate that electricity is converted to mechanical energy, light, or heat

is electric power

                   Electric Power = current x voltage

                   1 watt = (1 ampere) x (1 volt)

                   120 watt lamp = ??? x 120 volts = ??? = 1 amp

                   1,000 watts = 1kw

                   1,000 watts/hour = 1kwh

                   power = energy/time or energy = power/time = kwh (energy = J)

                   1kwh = 3.6 x 106J

                   5 cents/kwh = 100w lamp costs 0.5 cents/hour; the toaster is much more

expensive (those resistive – heat producing loads)


Chapter 35 – Electric Circuits

         

35.1 – A Battery and a Bulb

          To light up battery to bulb to battery must have a clear/complete path

                   A circuit must be completed; through the filament of the bulb

          Battery is a “pump” bulb is a machine – toaster, heater, hair dryer – the

circuit must be allowed to flow around the circuit, just like pipes

                    Flow continuous, no constrictions, no log jams

The values = the switch

35.2 – Electric Circuits

                   If e- can flow you have a circuit; stop flow … switch

                   Water leaking, electricity “leakage”; Pipe brakes water FLOWS, circuit

breaks flow of electricity STOPS

                   Switch, CB, wire cutters = faucet (end of “circuit”), valve (middle of “circuit”)

                   Circuits – Series & Parallel

35.3 – Series Circuits

                    DC battery systems

One Path

                   9v battery, 3 lamps … 3v lamps

                   Each device has same current (A); total resistance = resistance sum of

each device (Ω); current = voltage/resistance; Ohm’s law works

for each individual device; voltage drop (potential difference)

across individual devices is dependent of device resistance; larger

resistance requires larger charge to get through device (more heat

too); total voltage drop across devices = total system voltage 

                   Disadvantage – one device failure stops whole circuit; all devices are

dead

Advantage, less materials (wire) needed, so less expensive

35.4 – Parallel Circuits

                   AC House wiring systems

                    Multiple Paths, each device has it’s own path

                   Voltage = for each device; total current divided amongst each device,

current inversely proportional to resistance (Ohm’s law applies to

each branch); total current sum of individual currents; an increase

in circuits reduces overall resistance (more “pathways” results in

less resistance within the system

                   Disadvantage, more material (wire), so more expensive

                   Advantage, failure of a device will not result in total system failure

35.5 – Schematic Diagrams

          Show how systems work, which system of wiring is being used, and

 

Chapter 35 – Electric Circuits (Continued)

 

includes symbols for numerous devices, resistors, switches,

batteries, etc

          35.6 – Combining Resistors in a Compound Circuit

                   In series circuits 1 Ω + 1 Ω = 2 Ω (lamp + lamp = 2 lamps resistance)

                   In parallel circuits 1 Ω + 1 Ω = ½ Ω (twice the path, half the resistance)

                   Parallel + Series … 8 Ω (Series) + [8 Ω + 8 Ω] (parallel) = 8 Ω + 4 Ω = 12 Ω

                   Figure 35.10 & 35.11, page 556) show more complex versions of the same

resistance combinations

          35.7 – Parallel Circuits and Overloading

                   Causes heat, could melt wire – enter CB’s with magnetic and thermal

overload protection

                   Demand  loads are sometimes considered during design; if EVERYONE

turns on EVERYTHING ten systems – houses, apartments, office

buildings would fry (or be VERY expensive to build/buy; it must be

assume that everyone will NOT turn on everything when systems are

designed by electrical engineers (thus demand load is less that

everything but hopefully (mostly) more than occurs; hot day (or week)

& AC’s, etc go on, failures can occur and can be cascading, taking out

       huge areas of the city or country (8/14 – 15/2003.)

 


Chapter 36 – Magnetism 

         

36.1 – Magnetic Poles

          Attract and Repel

          Poles produce magnetic forces

          North-seeking

          South-seeking

          Like repel; opposite attract

          Electric charges CAN be isolates; magnetic can not

          36.2 – Magnetic Fields

                   Lines of force.

                   FROM the North.

TO the South.

More lines, nearer the poles, more force.

          36.3 – The Nature of a Magnetic Field

                   No Mag w/out Electricity; No E w/out Mag; No Mag w/out motion.

                   Electrons rotate and orbit – produce electric fields.

Iron, Nickel, Cobalt

          36.4 – Magnetic Domains

                   Clusters of electrons; lots in Iron.

                   Iron domains easy to align, thus make strong magnets.

                   Impose E field .. make a nailk a magnet.  For awhile.

                   Drop, heat magnet goes away.

          36.5 – Electric Currents and Magnetic Fields

                   Rt-hand rule(s).

Some Iron cores become saturated, strength maxes out.

So use Superconductors MRI’s, Mag-Lev Trains.

36.6 – Magnetic Forces on Moving Charged Particles

          E fields accelerate; Mag fields deflect electrons.

          Electrons towards the mag north pole.

          TV’s, particle accelerators.

36.7 – Magnet Forces on Current-Carrying Wires

          Wire jumps, deflects in Mag field WHEN wire carries current, a force

is exerted on the wire.

          36.8 – Meters to Motors

                   Galvanometers; current through wire deflects needle, either direct

                             voltmeter or induced current meter.

                   Motors armature, brushes, stator (split to reverse polarity.)

         

         


Chapter 36 – Magnetism (Continued)

 

          36.9 – The Earth’s Magnetic Field

Compass, points to North.

North reverses, time to time. 700,000, 870,000 , and 950,000  years ago.

                   Mag field caused by convection currents, dynamo effect with motions

in liquid core and motion of inner solid core.

 


Chapter 37 – Electromagnetic Induction

                    1831 - Farraday & Henry.

37.1 – Electromagnetic Induction

          Wrap wire around iron; run current through wire, get induced magnet,

                   turn on & off at will.

          Lots of wires, lots of magnet; few wires, weak magnet.

          Move magnet through wire coil get current in wire.

          37.2 – Faraday’s Law

                   Number of coils proportional to rate-size magnet field produced.

          37.3 – Generators and Alternating Current

                   Magnet moves around wire, wire moves around magnet; same effect,

                             make electricity.

                   Loop spins in mag field current flows, reverses, then flows again

                             i.e. AC electricity produced.

                   Turbines spun by … wind, steam, etc make Electricity.

          37.4 – Motor and Generator Comparison

                   Motor current flows, provides force around wire that rotates something

                              by deflection.

                   Generator, mag induction, mag makes current, produces electricity.

          37.5 – Transformers

                   Pairs of coils one field induces TO another field, changes voltage.

                   Primary and secondary coils.

                   More to fewer; fewer to more coils.

                   Primary Voltage / Number of turns = Secondary Voltage / Number of turns

                   Power in = Power out

                   V X I (amps) (primary) = V X I (amps) (secondary)

          37.6 – Power Transmission

                   120,000v down to 120v, Step-down transformers.

          37.7 – Induction of Electric and Magnetic Fields

                   E field created where mag field changes (moves); size of e field

                             proportional to rate of change of mag field.  Direction of e field

                             90 degrees to mag field.

                   M field created where e field changes (moves); size of Mag field

                             proportional to rate of change of e field.  Direction of mag field

                             90 degrees to e field.

         


Chapter 37 – Electromagnetic Induction (Continued)

 

          37.8 – Electromagnetic Waves

                   Stick in water makes waves; charged “stick” in space makes EM waves

                             in space.

                   EM waves composed of vib e & M fields each regenerates each other.

                             i.e. LIGHT energy carried by E & M Waves; EM Spectrum.

                   Speed of light.

                   Mag and E fields 90 degrees to each other. 

 

 

 


Unit 4 – Sound and Light

 

Chapter 25 – Vibrations and Waves

Vibrations, wiggles, carry energy; wiggles make waves.  Sound and earthquakes; light later Chapters.

25.1 – Vibration of a Pendulum

          Depends on length and Accel due to gravity (NOT mass dependent)

as: T = 2π √L/g

                   Short-legged (fast) and long-legged animals (slow)

25.2 – Wave Description

          Simple Harmonic Motion - sin wave – constant energy and speed.

          Crests, troughs, amplitude (distance between crests or troughs.)

          Wavelength (distance from top to top, or bottom to bottom.)

          Frequency - number of crests, troughs, to pass per minute.

          Hertz – frequency.

          Frequency = 1 / Period

          Period = 1 / Frequency

          Frequency is the INVERSE of Period

Freq = 2 Hz = Period of ½ Second

          1/3 Second Period = 3Hz Frequency

100 Hz = 100 vibrations / second

Period = 1/Freq = 1 vib / 0.1 Hz = 1 vib/0.1 vib/s = 10 Seconds

25.3 – Wave Motion

          The wave (front) moves … not the medium; sound leaves speaker

                   arrives at ear nothing gets to ear (eye) but the energy. Drop of

                   water, energy goes while water does nothing.

          Energy transfer … disturbance in medium … one particle to the next.

25.4 – Wave Speed

Speed depends on the medium; air/sound 330 to 350 m/s

(depends on temperature); 4X faster in water.

                   Wave speed = frequency X wavelength (or v = fλ)

m/s = cycles/second x m

                   1 meter wave … one wavelength passes point in one second = speed of 1 m/s.

                   SOUND:      160 Hz         2.13 m         340 m/s

                                      264 Hz         1.29 m         340 m/s

                                      396 Hz         0.86 m         340 m/s

                                                                             SAME!!

 

          V = d/t        10m cars … 2 x 10 m / 1 second = 20 m/s    (Ch 2)

          V = fλ         2 Hz       X       10 m   =   20 m/s                  (Ch 25)

 

Chapter 25 – Vibrations and Waves (Continued)

 

25.5 – Transverse Waves

          Motion of the medium (rope) is 90-degrees to wave direction

25.6 – Longitudinal Waves

          Motion of the medium (spring) SAME direction  as wave direction.

25.7 – Interference

          Reinforce – in phase - peaks TO peaks etc

          Cancel – out of phase - peaks TO troughs (or partially

          Water , sound, light.

25.8 – Standing Waves

          Stationary nodes

          Moving Anti-nodes (the not so good parts of buildings.)

25.9 – The Doppler Effect

          Siren (higher pitch AT you; lower pitch GOING away)

Stars (Blue coming AT you; red going away)

RADAR Detectors Reflected waves from you shortened to cop;

too short = too fast = ticket

25.10 – Bow Waves

          You are at the leading edge of the wave, a boat through the water, you

are at the top of the pyramid with the rest of the wave fanning out

behind you.

25.11 – Shock Waves

          You are at the leading edge of the wave a plane breaking the sound

                   barrier;  you are at the top of the pyramid with the rest of the

                   wave fanning out behind you.

          Plane goes over THEN you hear the “sound wave” later


Chapter 26 – Sound

          A room full of ping pong balls.

                   Tuning fork in a glass of water.

26.1 – The Origin of Sound

          Sound is the vibration of material objects.

Guitar strings, drum, saxophone (vibrating reeds.)  One thing makes the other thing, bell, inside drum, or soundboard vibrate.

                   Pitch = the sound made, that we hear as music.

                   You hear 20 – 20K Hz (before heavy iPod use.)

                             20 = Infrasonic; 20K+  = Ultrasonic.

          26.2 – Sound in Air

Longitudinal, Compressions (hi pressure) and Rarefactions (lo pressure)

          of air molecules.

Pulse, not the air, travels. 

Tuning Fork alternately compresses and rarefies air in pipe.

          26.3 – Media That Transmit Sound

                   Sound transmitted through a medium … air … no air … no sound.

                   Rocks under water, rocks in air, but not rocks (alarm clock) in vacuum.

          26.4 – Speed of Sound

                   Dry air, 0° C, 330 m/s (1,200 km/hr)

                   Lightning FLASH, then …. BOOM

                   Each degree increase in temp results in 0.60 m increase in speed of

                             sound.  So room temp (20° C) speed of sound is 340 m/s.

                   Speed does NOT depend on density but on ELASTICITY (the ability to

                             change shape), higher = higher; steel = air X15, water = air X4. 

          26.5 – Loudness

                   Intensity = Proportion to square of amplitude of wave. 

                   Loudness is subjective (the hearing loss is not.  Varies as a log (powers

of ten) of intensity; measured in dBs, decibels, Alexander

Graham BELLS.  10dB = 10X 0 dB, 20 dB = 100X 0 dB

(60 = 100X 40 etc.)

          26.6 – Forced Vibration

                   Tuning Fork by itself is not much “sound”.  On a table, Fork “uses” the

                             table to make MORE sound; the table becomes a soundboard,

                             table is forced to vibrate with fork, by fork.

          26.7 – Natural Frequency

                   All objects have one … just drop it and hear.  Things will vibrate

                             (resonate) at many different frequencies.  Natural requires least

                             amount of energy to get going.

         


Chapter 26 – Sound (Continued)

 

          26.8 – Resonance

If you force any object to vibrate at Natural Frequency it is said to be

                             resonating (resounding or sounding again.)

                   Pump swing at natural freq (deliver a rhythm in tune with the Natural

                             Freq) and the amplitude increases.

                   Sing and the glass breaks, molecules cannot move fast enough to avoid

                             breaking. 

Tuning Fork to Tuning Fork, start one and let it start the other same

          forks. 

Same with radio, tuning equipment to receive the frequencies of the

          desired station. 

Marching over bridge you want to be out of tune so as not to knock the

          bridge down.  Tacoma Narrows Bridge is a great example of or

forced Natural Freq and resonance multiplying the amplitude of

a wave, to breaking!

          26.9 – Interference

                   Constructive  ...  Bigger

                   Destructive  … Smaller or gone

                   For transverse AND longitudinal waves.

                   In phase and out of phase (con and discordant)

Dead spots in rooms or multi foci (hear other conversation from great

          distances), whisper great distances.

Noise canceling, making BOSE rich!!!! Sleep on planes ….

          26.10 – Beats

                   Special case for interference; beats like overlapping combs some areas

                             are reinforced some cancelled that woo WOO woo WOO sound

                             when in step louder (two compression overlap, sound is max)

when out of step softer (rarefactions overlap, sound is minimum.)

                   My 70 steps to your 72 steps to cover the same distance; we are lined

                             up every once in a while.

                   Oscilloscope – superimpose 2 waves “see” the BEATS Loud …

and … faint (fig 26.17.)

                   If 262 Hz and 266 Hz interfere with each other 4 beats (maxs/mins)

                             result 266 – 262 = 4 Hz, resultant tone half way in between at

264 Hz (the ear averages the freq.)  262 and 272 = 10 Hz most

cannot hear this; if beats greater than 10, too rapid to be heard. 

                   Tune piano with fork, you’re good when the beats … go away.

 


Chapter 27 – Light

(PPT ON OPTICAL ILLUSIONS!!!!!!!!!!!!!!!!!)

                    Sun primary source of light, we see it, but most of what we see is

reflected (not the absorbed light frequencies.)

27.1 – Early Concepts of Light

Socrates, Plato, Euclid

          Why do we not see something until our eyes are cast upon it?

                   Streamers?  Filaments?

          Light as waves!!!!!!!!!  Bends, diffracts (Ch 31), around corners, like water.

Empedocles – Ever heard of him???

          Light as particles …. Travels is straight lines, like a bullet (sort of.)

Newton!!!!!!!!!!!  Heard of HIM!!!!  (and Huygens too)

Einstein, photoelectric effect, photons (i.e. massless particles of energy.)

NOW – Light is both, but not proven to be both AT THE SAME TIME.

          27.2 – The Speed of Light

                   Hard to measure, Galileo tried but no distances big (mirror and back)

 enough to measure.  Mt to Mt no go as well.

                   Roemer, 1675, moons of Jupiter, while not quite accurate, showed

distance deference's relating back to Earth/Jupiter motions (6

months apart) vs. the speed of light travel into his telescope

(Fig 27.2.) Distance 6 months apart vs. time for observation

yields the speed of light.  Huygens figured out the error the light

was later due to the greater distance not the moon Io. 

                   So distance 300,000,000 km and the correct 17 min, or 1,000s (not

                             Roemer’s 22 min) you can calculate speed of light as 300,000

                             km/s or 3,000,000 m/s.

Speed of light = difference in distance to Io / time “delay” or

300,000,000 km / 1,000 s = 300,000 km/s

                   Michelson’s, 1880, Nobel winning experiment (Fig 27.3) proved the

                             same thing with only Mt to Mt distances (35 km.)  70 km vs.

correct spin speed results in trip time and thus speed of light.

299,920 km/s or 300,000 km/s.

                   CONSTANT in a vacuum, i.e. space … 8 min Sun to Ea, 7. trips/s

                             around Ea, 4.0, 4.2, 4.3 to nearest star Alpha Centauri.

                   Distance light travels in 365 days = LY or pg 408, 9.5 X 1012 km.

         


Chapter 27 – Light (Continued)

 

27.3 – Electromagnetic Waves

                   Light = Electric charges (electrons in atoms.)

                   Wave part Magnetic part Elect = EM Waves

                   EM Waves = EM Spectrum

                   Lowest visible = RED

                   Highest VIOLET = RED X2

                   Lower than visible infrared = Heat Lamp.

                   Higher than visible = Ultraviolet = Sunburn.

                   Radio; Micro; Infrared; Visible; Ultraviolet; X-Rays; Gamma Rays.

          27.4 – Light and Transparent Materials

                   Color = vibrations

                   Visible light 1014 Hz, very fast

                   Inertial (mass) must be small i.e. electrons.

                   Transparent = Glass & Water

                   Electrons “on springs” vibrate when hit by light energy.

                   Natural Frequency = different spring strength = color you see.

                   Glass not transparent to UV or IR; Greenhouse Effect; visible in UV/IR

                             out NOT.

                   Vibration through glass causes light to slow down;

water .75 of “c”; glass .67 of “c”, after passing through it’s back

to full “c”.

          27.5 – Opaque Materials

                   Absorb + or – w/o reemission.

                   Metals vibration reemit light i.e. shinny reflection.

                   Atmos transparent to visible & some IR; almost opaque to UV.

                   UV in sunburn even with clouds and off sand and snow.

          27.6 – Shadows

                   Where the Sun’s rays cannot reach.

                   Umbra (really dark) and Penumbra

          27.7 – Polarization

                   Transverse waves, can be blocked …

                   From Sun or Flashlight waves go in all directions.

Through first sheet and they are up/down or left/right.

                   Through the second sheet they are either partly or completely gone.

          27.8 – Polarized Light and 3-D Viewing

                   The pictures I cannot “see” in 3-D of at all.

                   Two projectors … two colors … 3-D.  Bugs Life etc.

 


Chapter 29 – Reflection and Refraction

         

29.1 – Reflection

                   Snell’s Law. Angle of incidence = angle of reflection.

          29.2 – The Law of Reflection

          29.3 – Mirrors

                             Flat vs. Concave vs. Convex.

          29.4 – Diffuse Reflection

          29.5 – Reflection of Sound

                             Mechanical wave “acts” like EM, like light.

          29.6 – Refraction

                             Bending, contact between different medium of different

                                      densities (speeds of light.)

          29.7 – Refraction of Sound

                             Bend at contacts between different temperatures, densities, of air.

          29.8 – Refraction of Light

                             Bends at contacts between different densities of whatever the

                                      medium, air, water, glass.  n = c/v  Index of Refraction

                                      (Diamonds vs. Cubic Zirconium.)

          29.9 – Atmospheric Refraction

                             Mirage; different temperatures, humilities in the air.

          29.10 – Dispersion in a Prism

                             Into = c; out side on the other side = c; inside less than c and

                                      different wave lengths, colors, offset different amounts; get

                                      rainbow.

          29.11 – The Rainbow

                             Dispersion,  refraction.  Circle in the air, from airplane; bow

                                      With cutoffs at the grounds surface.

          29.12 – Total Internal Reflection

                             Fibre Optic Cable.


Chapter 31 – Diffraction and Interference

 

                   (Newton’s tiny Particles)

31.1 – Huygens’ Principle

          Wave fronts are made of tinier waves

                   Straight or curved Figs 31.1-3 (pg. 481)

          Applied to reflection and refraction Fig 31.4 (pg 482.)

          31.2 – Diffraction

                   Bending of light … waves … particles.

                   Larger slit less bending; narrower slit more bending.

                   Edges to shadows.

                   Problem in microscopes, enter Electron Microscopes.

Dolphins and ultrasound detection.

          31.3 – Interference

                   Con and Destructive again.

                   Interference Patterns i.e. the falstad.com website.

                   Light and water do the same things; erosion control on the shorelines.

          31.4 – Young’s Interference Experiment

                   1801 Brit monochromatic light at two pin holes get light (constructive

interference) and dark (destructive interference) fringes against

screen beyond holes.

                   Diffraction Grating and room lights. 

          31.5 – Single-Color Interference from Thin Films

                   The rainbows in soap bubbles; thickness of the film surface versus the

                             color you see in the bubbles.

                   Glass, air, glass … can see con and destructive interference.

          31.6 – Iridescence from Thin Films

                   Gas and oil on the road; it’s all about the thickness of the film and what

                             colors are absorbed and transmitted.

                   Interferometers measure tiny distances (offset, displacements) using

 interference.

          31.7 – LASER Light

More light sources incoherent; arrives in many phases Fig 31.25 – 26

and frequencies (colors) Fig 31.25.

                   LASER is coherent; phases lined up, and ONE frequency Fig 31.27.

          31.8 – The Hologram

                   LASER, photographic plate, mirror to made a 3-D “virtual” object.

                   On film, cut in half (many times), and “the object” is still preserved on

                             each “piece” of film.

                   X-ray holograms.

 

 

Chapter 15 – Special Relativity – Space and Time

         

15.1 – Space-Time

                   IS the Special Theory of relativity.  Easier than General Theory

                             Of Relativity.  Space and time are “special”, acceleration

                             And length are “general”.  Newton was Space AND Time;

Einstein was Space-Time; 4th dimension after L-W-H; can

be dilated.  The more massive the larger the “depression in

Space-Time = “Gravity” …Sun makes a big “hole” and we  circle the drain (with forward speed) around the Sun.  Black Hole “Big Daddy Hole in Space-Time.

          15.2 – Motion is Relative

                             Not moving … “X” vs. moving “X” & “Y” left and left, left and

                                      right, or right and right, or up and down etc.

          15.3 – The Speed of Light is Constant

                             A, THE Constant, 3.0 X 108 m/s in a vacuum.

          15.4 – The First Postulate of Special relativity

                             ALL “Frames” are arbitrary, EVERYTHING is moving

                                      “relative” to each other.  Uniform motion = standing still,

                                      throwing ball in a “moving” airplane.

          15.5 - The Second Postulate of Special relativity

                             C = C = C whether you are still or moving in the vacuum of

                                      space; you still light goes by at C; you moving at 0.9 C,

                                      light still goes by at C, go figure!!!! Pg 286 new book,

page 218 old.

          15.6 – Time Dilation

                             If you are going C (you cannot due to your mass and thew need

                                      for SO much energy to accelerate you to C) then time …

freezes … biological process …STOP. 

 

                             Pg 218, Fig 15.9 The moving “Light Clock”.  Video of the

                                      experiment.  t = initial to / root 1 – (v2 / c2)  Figure 15.11

                                      (The Train.)

          15.7 – The Twin Trip

                                50% C      =    1 yr     =     1.15 yrs       so what

                                87% C      =    1 yr     =          2 yrs        better

                             99.5% C      =    1 yr     =        10 yrs       now your talking!

          15.8 – Space and Time travel

                             2 Stationary objects “flashes” at same interval 1.., 2.., 3.., 4.., 5...

                             2 Moving objects “flashes NOT the same interval:

          Chapter 15 – Special Relativity – Space and Time (Continued)

 

Towards each other … “flashes” “more” frequent.

                                                                    1., 2., 3., 4., 5.

                                      Away from each other …”flashes” “less” frequent.

                                                                   1…..., 2…...., 3……, 4……., 5.....…

                                      Procyon, a star ... 11.4 lyrs away; go there @ 99% ....

                                                There and back about 23 yrs .... you 3 yrs older,

                                                that’s not too bad!


Chapter 16 – Special Relativity – Length, Momentum, and Energy

         

16.1 – Length Contraction

                   Earth, base ball, ruler gets ... flatter ... shorter as it increases its

Speed towards C.  Length = Lo root 1 – (v2 / c2) 

          16.2 – Momentum and Inertia in Relativity

                             Momentum (Relativistic) = p = mv/ root 1 – (v2 / c2)

          16.3 – Equivalence of Mass and Energy

                             Uh ... E = mc2  well actually ETotal = mc2/ root 1 – (v2 / c2) 

          16.4 – Kinetic Energy and Relativity

                             KE = mc2/ root 1 – (v2 / c2)  -  mc2  Reduces to ½mv2

                             NEAR C Momentum + E = ∞.  Can’t accelerate something, with

                                      mass, to C; takes TOOOOOOOO much E.

 

          16.5 – The Correspondence Principle

                             Relativity vs. Newton

                                      t = to/ root 1 – (v2 / c2) ;  to/ root 1 – 0 = to 

 

L = Lo = root  1 – (v2 / c2) ; Lo root 1 - 0 = Lo

 

P = mv/ root 1 – (v2 / c2)  ;  mv/ root 1 – 0 = mv

 

          16.5 – Gravity, Space, and a New Geometry

                             4th dimension ... 3-D space + time. 

                             Flat, Spherical, or Saddle-shaped???

                             Find the “geodesic” = shortest distance between A & B.

                             Gravity waves, novas, local disturbances that, in turn, cause new

                                      stars planets, & us.

16.6 – Tests of General Relativity

                             Precession (predicted orbit precession-not in Newtonian

                                      presentation), Deflection of Starlight (gravitational

                                      “lenses”), and Gravitational Red Shift (light traveling

                                      “against” gravity.)

 


Unit 6 – Atomic and Nuclear Physics

 

Chapter 38 – The Atom and the Quantum

         

38.1 – Models

                   Truthful vs. Useful; “Planetary Model” of atoms.

                             The BIG explains the small ... KISS.

                   Bohr model – the way it seems to be.

          38.2 – Light Quanta

                             Light – waves(?); interference λ = h/momentum (De Broglie)

                                         Particles(?); photons (marbles)

   QUANTA ...  Quantum Mechanics

   Photons do NOT rest ... ONE speed.

                             h = 6.6 X 10-34 Js

                             E = hf  E = the Quanta of light, the particle.

          38.3 – The Photoelectric Effect

                             Al’s Nobel Prize.  Why this ?  Could be understood; E = mc2 was

                                      way over everyone’s head.

Photon’s ... move electrons in certain metals

Waves of e- = e- microscopes.

          38.4 – Waves as Particles

                             Light in space.

          38.5 – Particles as Waves

                             Light in solid matter.

                             De Broglie ALL matter can be viewed as waves.

          38.6 – Electron Waves

                             De Broglie

          38.7 – Relative Sizes of Atoms

                             Size depends on electric charge in the nucleus. 

          38.8 – Quantum Physics

                             Imprecise, Albert hated this, on a microscopic level.

          38.9 – Predictability and Chaos

                             Statistics and probability never know where the e- is but it’s in its

                                      “orbit” somewhere; they move fast ... as soon as you “see”

                                      them ... their gone anyway.  Moguls on the ski slope.

CHAOS THEORY ... Jurassic Park.

 


Chapter 39 – The Atomic Nucleus and Radioactivity

         

39.1 – The Atomic Nucleus

                   p’s & n’s is nucleus; BOUND by STRONG force (a bunch of +’s

                             REALLY close together MUST be bound strongly i.e. lots

of ENERGY when you get them apart!!!

                   ZNA  Z = Portons i.e. ATOMIC NUMBER;

A = P’s & N’s combined.

                             Neutrons are the “separators” needed to INCREASE the distance

(a little) between Protons; if they weren’t there the the

strong force would be HUGE.

                             Nucleus SMALL low volume, high density. Break these bonds,

you got a bomb.

                             H = 1 p and 1 e-.  Mass = 1;  He = 2 p, 2 n, and 2 e-.  Mass = 4

                             Deuterium = “Heavy” water = 1H2  1 p & 1 n.

                             Tritium = 1H3  1 p & 2 n’s.  β-decay.

          39.2 – Radioactive decay

                             α = He atom          2He4 p’s or p’s & n’s

β = e- out fast, cue ball on the table.

γ = EM at very high energy, frequency end; ouch  - burn, death,

          kill.

          39.3 – Radiation Penetration Power

                             α lo, β medium, & γ high.

          39.4 – Radioactive Isotopes

                             Able to release a p, or e-.

          39.5 – Radioactive Half-Life

                             How long for half to decay to something else; had 1,000 of

                                      them how long to get to 500 of them?

                             Rb-Sr vlong half-life; there are elements with half-lives longer

                                      than the age of the universe.

          39.6 – Natural Transmutation of Elements

                             Happens in the “wild” all the time.  C-14, Rb-Sr, U-Th.

          39.7 – Artificial Transmutation of Elements

                             The guys above 92 Uranium are all ours.

Various kinds of Decay depending the element of choice.  Hit it with a cue ball, probable a e-, and see what happens.

          39.8 – Carbon dating

                             Good to 40-70 thousand years.

          39.9 – Uranium Dating

                             It’s 4.6 BYO has to come from somewhere, very lage Half-life.

          39.10 – Radioactive Tracers

          Chapter 39 – The Atomic Nucleus and Radioactivity (Continued)

 

Drink Barium and get scanned.

          30.11 – Radiation and You

                             MRI, Various scanners CAT etc, Phototommagraphy, X-Rays

                             All effect DNA i.e. move e- around.

                             Α not so bad but not effective; β & γ effective but dangerous to

 you; you problem better be worth the potential damage

that can happen TO you.

                             Polonium and the spy business.


Chapter 40 – Nuclear Fission and Fusion

 

40.1 – Nuclear fission

                    Bombs; bad news waste, where to store?

                   Chain reactions – can’t stop till they are “finished”.

                   Critical Mass – one fission event produces, at least, one more

                             event.

40.2 – The Nuclear Fission reactor

                   Way back in the 1800’s, had them, but very ... leaky ... scary.

40.3 – Plutonium

                   92 highest, naturally, occurring element on Earth; Pu = 94, it’s

                             here cause we make it; MARS PPT(?)

Pu = U = Breeder Reactor.

40.4 – The Breeder reactor

40.5 – Mass-Energy Equivalence

                   E = mc2.

40.6 – Nuclear fusion

                   Fusion “together”

The Sun H to He, etc. Our to Carbon; where did the rest come

          from ...?  GOOD “waste” = H2O.

Bigger atoms (Pu) have e’s and p’s closer together ... more ...

          unstable; reactions easier to arrange.

High energy Pool Tables.

CLEAN, HOOOOT, hard to “contain”.

COLD Fusion, a hope, a dream.

40.7 – Controlling Nuclear Fusion

                   Sure for perhaps ...10-9 seconds ... maybe. 

University of Chicago

                   LLL – Lawrence Livermore National Laboratory.

 

 

 

 

 

 

 

 

 

 

 

 


Appendices

 

A.   Units of Measurements

B.    Working With Units in Physics

C.   Graphing

D.   Vector applications

E.    Exponential Growth and Doubling Time

F.    Equations of Physics

G.   Preparing for a Career in Physics

 

Glossary

 

Index


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