MECHANICS

MEASUREMENT

Basic Units

Disc 01-01

basic unit set

Show a clock with a second sweep, meter and yard sticks, and kilogram and pound mass. (PIRA # 1A10.10)

Error and Accuracy

Disc 16-12

Gaussian curve

A commercial device for the overhead projector where ball bearings roll through an array of nails into parallel chutes. (PIRA # 1A20.10)

Coordinate Systems

Vectors

Disc 01-07

3-D vector components

Metal arrows define a three dimensional coordinate system. An arbitrary vector is viewed in the three planes. (PIRA # 1A40.10)

Disc 01-04

vector components

Animation. (PIRA # 1A40.14)

Disc 01-02

vector addition (parallelogram)

Animation. (PIRA # 1A40.31)

Disc 01-03

vector addition (head to tail)

Animation. (PIRA # 1A40.33)

Disc 01-05

vector dot products

Animation. (PIRA # 1A40.70)

Disc 01-06

vector cross product

Animation shows vectors superimposed on a right hand. (PIRA # 1A40.75)

Math Topics

Disc 05-12

radian disc

A flexible strip of plastic equal to the radius is bent around the edge of a circle. (PIRA # 1A50.10)

Scalling

Disc 08-07

2:1 scaling

"Bridges" of the same geometry are scaled in every dimension by 2:1. Masses placed in the center of the bridges are also scaled 2:1. (PIRA # 1A60.30)

Disc 14-16

scaling cube

Cut a cube painted black into 27 smaller cube. When dismantled, the unpainted surfaces show the increase in surface area. (PIRA # 1A60.40)

MOTION IN ONE DIMENSION

Velocity

Disc 01-09

bulldozer on moving sheet

Identical bulldozers run at constant speed, one on a moving paper, to show how velocities add and subtract. (PIRA # 1C10.10)

Disc 01-08

constant velocity (airtrack)

Dots are superimposed on the screen every half second to mark the position of the air glider. (PIRA # 1C10.25)

Uniform Acceleration

Disc 01-14

guinea and feather

Metal and paper discs are placed in identical tubes. (PIRA # 1C20.10)

Disc 01-12

string and weights drop

Drop strings with weights. (PIRA # 1C20.20)

Disc 01-11

constant acceleration

Dots marking the position of the glider are superimposed on the screen as the glider accelerates down an inclined air track (PIRA # 1C20.30)

Disc 01-10

rolling ball on incline

Additions to the blinky track: magnetic strips can be removed from the track showing all d's, delta d's, and delta v's. Place these strips vertically to show position, velocity, and acceleration vs time. Graphs are simulations on disc but real at U of Wash. (PIRA # 1C20.41)

Measuring g

Disc 01-13

reaction time falling meter stick

Have a student catch a falling meter stick and relate the distance dropped to the reaction time. (PIRA # 1C30.55)

MOTION IN TWO DIMENSIONS

Displacement in Two Dimensions

Disc 02-07

velocity vector addition

The ball in a tube done horizontally on the table viewed from above with the camera. (PIRA # 1D10.10)

Disc 05-13

cycloid generator

Large and small cylinders are joined coaxially. A spot on the larger cylinder moves in a cycloid when the smaller cylinder is rolled on its circumference. (PIRA # 1D10.20)

Velocity, Position, and Acceler

Disc 02-09

sliding weights on triangle

Lengths and angles of a wire frame triangle are chosen so that beads sliding down the wires traverse each side in the same time. (PIRA # 1D15.41)

Motion of the Center of Mass

Disc 03-21

center of mass disc

Throw a disc with uniform distribution and then offset the center of mass. (PIRA # 1D40.11)

Disc 03-27

air table center of mass

A weighted block glides across an air table. (PIRA # 1D40.22)

Central Forces

Disc 05-17

ball on cord

A string with a rubber ball on one end passes through a plastic sleeve and weights are attached to a loop at the other end. (PIRA # 1D50.20)

Disc 05-19

plane on string

A model plane flies around on a string defining a conical pendulum. (PIRA # 1D50.26)

Disc 05-20

roundup

A toy person stands on the inside wall of a rotating cylinder. (PIRA # 1D50.30)

Disc 05-21

whirling bucket of water

Rotate a bucket of water in a vertical circle. (PIRA # 1D50.40)

Disc 05-18

coin on coat hanger

A coin is placed on the flat of the hook of an elongated coat hanger and twirled around. (PIRA # 1D50.45)

Disc 05-24

spinning chain

Spin a flexible chain rapidly enough that it acts as a solid object. (PIRA # 1D50.70)

Deformation by Central Forces

Disc 05-22

centrifuge hoops

A flexible hoop becomes oblate as it is rotated. (PIRA # 1D52.10)

Disc 13-17

parabolid of revolution

A cylindrical container with some water is rotated at a constant speed. (PIRA # 1D52.20)

Disc 13-18

rotation water troughs

Two water containers are mounted on a rotating table. A rectangular container mounted radially shows half a parabola, and another formed in an arc of constant radius stays level. (PIRA # 1D52.21)

Disc 05-23

water and mercury centrifuge

Water and mercury spin in a glass sphere. (PIRA # 1D52.35)

Disc 05-25

rotating rubber wheel

A rubber wheel stretches to a larger radius when spun. (PIRA # 1D52.61)

Centrifugal Escape

Disc 05-14

circle with gap

Roll a ball around a circular hoop with a gap. (PIRA # 1D55.10)

Disc 05-16

spinning disc with water

Red drops fly off a spinning disc leaving traces tangent to the disc. (PIRA # 1D55.23)

Disc 05-15

rotating disc with erasers

Place erasers on a disc at various radii and rotate until they fly off. (PIRA # 1D55.30)

Projectile Motion

Disc 02-03

vertical gun on car

A ball is shot up from a moving cart and falls back into the barrel. (PIRA # 1D60.10)

Disc 02-04

vertical gun on accelerated car

Two cases: vertical gun on a car on an incline, and on a car accelerated by a mass on a string. (PIRA # 1D60.16)

Disc 02-01

shooter/dropper

Drop one ball and simultaneously project another horizontally. (PIRA # 1D60.20)

Disc 02-02

monkey gun

The apparatus consists of a blow gun with dowel projectile and electromagnetic release. (PIRA # 1D60.30)

Disc 02-06

range gun

Fire a spring loaded gun at various angles. (PIRA # 1D60.40)

Disc 02-05

air table parabolas

Pucks are projected across a tilted air track. (PIRA # 1D60.55)

RELATIVE MOTION

Moving Reference Frames

Disc 02-08

bull dozer on moving sheet (2D)

The bulldozer moves across a sheet moving at half the speed of the bulldozer or at the same speed. (PIRA # 1E10.10)

Rotating Reference Frames

Disc 06-13

Foucault pendulum

Look at the plane of swing at six ten minute intervals. (PIRA # 1E20.10)

Coriolis Effect

Disc 06-14

Coriolis effect

Roll a ball across a slowly rotating turntable. (PIRA # 1E30.28)

NEWTON'S FIRST LAW

Measuring Inertia

Disc 08-24

inertia balance

Place masses on a platform supported by horizontal leaf springs. (PIRA # 1F10.11)

Disc 02-14

foam rock

Hit a real rock and then a foam rock with a heavy mallet. (PIRA # 1F10.25)

Inertia of Rest

Disc 02-13

inertia ball

A mass is suspended between two cords. Pull slowly or jerk on the lower cord. (PIRA # 1F20.10)

Disc 02-15

tablecloth pull

Pull a low friction tablecloth from under a place setting. (PIRA # 1F20.30)

Disc 02-16

eggs and pizza pan

Place a pizza pan on three beakers, place cardboard tubes on the pan directly above the beakers, and eggs on the tubes. Knock out the pizza pan. (PIRA # 1F20.35)

Disc 02-12

shifted air track inertia

Move the air track under an air track glider. (PIRA # 1F20.50)

Inertia of Motion

Disc 13-14

water hammer

Evacuate a glass tube containing water. (PIRA # 1F30.21)

Disc 02-17

pencil and plywood

Use a CO2 extinguisher to fire a pencil through a 1/2" plywood. (PIRA # 1F30.50)

NEWTON'S SECOND LAW

Force, Mass, and Acceleration

Disc 01-15

string and weight acceleration (air

Three cases of an air glider pulled by a falling weight. (PIRA # 1G10.10)

Disc 01-17

acceleration with spring (airtrack)

An air track glider is pulled by a small spring hand held at constant extension. (PIRA # 1G10.16)

Disc 01-16

Atwood's machine

The small weight is removed after a period of acceleration and the resulting constant velocity is measured. (PIRA # 1G10.40)

Accelerated Reference Frames

Disc 01-19

candle in dropped jar

Drop a closed jar containing a burning candle. (PIRA # 1G20.10)

Disc 01-18

dropped slinky

Hold a slinky so some of it extends downward, then drop it to show the contraction. (PIRA # 1G20.45)

Disc 02-11

local vertical with acceleration

Place a liquid accelerometer on an air track glider on an inclined air track (PIRA # 1G20.70)

Disc 13-16

accelerometers

Two jars of water, one has a light ball suspended from the bottom, the other has a heavy ball suspended from the top. (PIRA # 1G20.76)

Complex Systems

NEWTON'S THIRD LAW

Action and Reaction

Disc 02-18

reaction gliders

Burn a string holding a compressed spring between two air gliders. (PIRA # 1H10.15)

Disc 02-21

fan car with sail

A sail is placed in front of a battery powered fan on a cart. (PIRA # 1H10.20)

Disc 02-25

helicopter rotor

A symmetric propeller deflects air down, causing upward lift. (PIRA # 1H10.25)

Recoil

STATICS OF RIGID BODIES

Finding Center of Gravity

Disc 03-20

irregular object center of mass

Suspend an irregular object from several points and find the center of mass with a plumb bob. (PIRA # 1J10.12)

Disc 04-15

meter stick on fingers

Slide your fingers under a meter stick to find the center of mass. (PIRA # 1J10.20)

Exceeding Center of Gravity

Disc 03-26

toppling cylinders

The standard leaning tower and an upright cylinder that topples when the cap is removed. It has two balls in the tube. (PIRA # 1J11.11)

Disc 03-24

double cone on incline

The double cone appears to roll uphill. (PIRA # 1J11.50)

Stable, Unstab., and Neut. Equi

Disc 03-19

stability

Balance a cone, show a block is stable and a sphere is neutral. (PIRA # 1J20.11)

Disc 03-23

clown on rope

A toy clown rides a unicycle on a wire. (PIRA # 1J20.45)

Disc 03-22

chair on pedestal

Hide heavy weights in the ends of a chair's legs so it will balance on a vertical rod placed under the seat. (PIRA # 1J20.51)

Disc 04-19

broom stand

Spread the bristles and a straw broom will stand upright. (PIRA # 1J20.55)

Resolution of Forces

Disc 04-03

load on removable incline

Place a cart on a removable 30 degree incline. (PIRA # 1J30.10)

Disc 04-02

clothesline

Hang a 5 newton weight from a line and pull on one end of the line with a spring scale. (PIRA # 1J30.25)

Disc 04-08

horizontal boom

The tension in the wire is measured with a spring scale for two different boom structures. (PIRA # 1J30.40)

Disc 04-01

force board

This looks like a magnetic vertical force board. A circle is marked with angles every 10 degrees. (PIRA # 1J30.50)

Disc 02-10

sailing upwind (airtrack)

Use a skateboard cart with a foam core sail. (PIRA # 1J30.60)

Disc 04-21

egg crusher

A raw egg can be squeezed between two hard foam rubber pads with a force of over 150 lbs. (PIRA # 1J30.75)

Static Torque

Disc 04-10

torque bar

Use wrist strength to lift a weight suspended at various distances from the handle. (PIRA # 1J40.10)

Disc 04-12

torque wrench

A torque wrench is used to break aluminum and steel bolts. (PIRA # 1J40.15)

Disc 04-14

balancing meter stick

Use a meter stick, suspended at the center, as a torque balance. (PIRA # 1J40.20)

Disc 04-11

hinge board

Use a spring scale to lift a hinged board from various points along the board. (PIRA # 1J40.21)

Disc 04-13

torque wheel

Use a wheel with coaxial pulleys of 5, 10, 15, and 20 cm to show static equilibrium of combinations of weights at various radii. (PIRA # 1J40.25)

Disc 04-16

bridge and truck

A plank rests on two spring scales forming a bridge. Move a toy truck across. (PIRA # 1J40.40)

Disc 04-17

Roberval balance

Neutral equilibrium is maintained at any position on the platform. (PIRA # 1J40.50)

Disc 04-09

arm model

Use an arm model simulating both biceps and triceps muscles to throw a ball. (PIRA # 1J40.75)

APPLICATIONS OF NEWTON'S LAWS

Dynamic Torque

Disc 04-18

ladder forces

A real ladder leans against the wall. Animation shows the forces as the ladder moves. (PIRA # 1K10.20)

Disc 06-07

spool with wrapped ribbon

The sides of the spool are made of clear plexiglass (PIRA # 1K10.30)

Disc 03-25

loaded disc

A loaded disc can roll up an incline. (PIRA # 1K10.50)

Friction

Disc 03-05

surface dependence of friction

Place brass blocks on an incline with four surfaces: teflon, wood, sandpaper, and rubber. (PIRA # 1K20.10)

Disc 03-04

weight dependence of friction

Add mass to a board pulled along the table with a spring scale. (PIRA # 1K20.15)

Disc 03-03

area dependence of friction

A 2X12 is pulled along the bench top while resting on either the narrow or wide face. (PIRA # 1K20.20)

Disc 03-02

static vs. sliding friction

Show that static friction is greater than sliding friction with a spring scale and block. (PIRA # 1K20.30)

Disc 03-06

stability of rolling car

A toy car slides down an incline with either front or rear wheels locked. (PIRA # 1K20.40)

Disc 03-01

air track friction

Show there is little friction on an air track. (PIRA # 1K20.90)

Pressure

Disc 04-20

bed of nails

Break a block on the chest of a person lying on a bed of nails. (PIRA # 1K30.10)

GRAVITY

Univ. Gravitational Constant

Disc 07-23

Cavendish balance

The commercial device with video over a 1 1/2 hour period. (PIRA # 1L10.30)

Orbits

Disc 07-21

sections of a cone

The standard wood cone. (PIRA # 1L20.40)

Disc 07-22

ellipse drawing board

The two nail and string method of drawing on paper. (PIRA # 1L20.51)

WORK AND ENERGY

Work

Disc 03-07

pile driver

Drop a weight onto a nail in wood. (PIRA # 1M10.20)

Simple Machines

Disc 04-04

pulley advantage

Hang a 10 newton weight on a string passing over a pulley and measure the force with a spring scale, then hang the weight from a free running pulley. (PIRA # 1M20.11)

Disc 04-05

pulley and scales

This is a counter intuitive demonstration. A frame containing a spring scale and pulley hangs from another spring scale. Look it up. (PIRA # 1M20.15)

Disc 04-07

levers

A torque bar, spring scale, and pivot are used to illustrate the three classes of levers. (PIRA # 1M20.40)

Non-Conservative Forces

Conservation of Energy

Disc 03-14

nose basher / bb pendulum

A bowling ball pendulum is held against the nose and allowed to swing out and back. (PIRA # 1M40.10)

Disc 03-13

Galileo's pendulum

Intercept the string of a pendulum by a post at the bottom of the swing. (PIRA # 1M40.15)

Disc 06-09

loop the loop

A rolling ball must be released at 2.7 times the radius of the loop. (PIRA # 1M40.20)

Disc 03-12

energy well track

A ball can escape the energy well when released from a point above the peak of the opposite side. (PIRA # 1M40.25)

Disc 03-15

triple track energy conservation

Balls released from three tracks with identical initial angles rise to the same height independent of the angle of the second side of the "v". (PIRA # 1M40.33)

Disc 05-11

ballistic pendulum

The commercial swinging arm ballistic pendulum. (PIRA # 1M40.41)

Disc 06-08

Maxwell's yoyo

Release a large yo-yo and it will bottom out and wind up again. (PIRA # 1M40.50)

Disc 03-10

x-squared spring energy dependence

Measure the height of recoil on an air cart glider on an incline after compressing a spring different to different lengths. (PIRA # 1M40.63)

Disc 03-08

spring pong gun

A spring gun shoots standard and loaded ping pong ball to different heights. (PIRA # 1M40.64)

Disc 03-09

spring jumper

Compress a spring under a toy held down be a suction cup. (PIRA # 1M40.67)

Disc 03-11

high bounce paradox

Flip a half handball inside out and drop on the floor. It bounces back higher than the height from which it was dropped. (PIRA # 1M40.91)

Mechanical Power

Disc 03-18

Prony brake

Rotate a shaft against a constant frictional resistive force. (PIRA # 1M50.10)

LINEAR MOMENTUM AND COLLISIONS

Impulse and Thrust

Disc 05-09

egg in sheet

Throw an egg at a sheet held by two people. (PIRA # 1N10.20)

Disc 05-10

piledriver with foam rubber

A pile driver breaks a plastic sheet supported at the sides. Add a piece of foam rubber and the plastic does not break. (PIRA # 1N10.30)

Conservation of Linear Momentum

Disc 02-26

see-saw reaction carts

Two spring loaded carts repel each other on a balanced board. (PIRA # 1N20.10)

Disc 02-20

car on rolling board

Use a radio-controlled car on the board on a series of rollers. (PIRA # 1N20.15)

Disc 02-19

reaction gliders momentum conservati

Burn a string holding a compressed spring between two unequal mass air gliders. (PIRA # 1N20.20)

Mass and Momentum Transfer

Rockets

Disc 02-24

fire extinguisher wagon

Mount a fire extinguisher on a wagon with the hose attached to a half inch plumbing fitting directed to the rear. (PIRA # 1N22.10)

Disc 02-23

water rocket

Use a water rocket first with air only, and then with air and water. (PIRA # 1N22.20)

Disc 02-22

CO2 rocket

A small CO2 cartridge rotates a counterbalanced bar. (PIRA # 1N22.33)

Collisions in One Dimension

Disc 05-01

colliding balls

Two balls of equal mass collide, then balls of various mass ratios are used. Collisions with a string of equal balls are also demonstrated. (PIRA # 1N30.10)

Disc 05-03

elastic and inelastic collisions

Air gliders have springs on one end and the post/clay on the other. (PIRA # 1N30.30)

Disc 05-02

equal and unequal mass collisions

Equal and unequal mass air gliders. (PIRA # 1N30.33)

Disc 05-05

high bounce

Drop a softball on a basketball (1:3) mass ratio. (PIRA # 1N30.60)

Collisions in Two Dimensions

Disc 05-06

air table collisions (equal mass)

Vary the angle of impact between a moving and stationary air puck. Lines are drawn on the screen. (PIRA # 1N40.20)

Disc 05-07

air table collisions (unequal mass)

Elastic collisions with unequal air pucks. (PIRA # 1N40.21)

Disc 05-08

air table collisions (inelastic)

Inelastic collisions between equal and unequal mass air pucks. (PIRA # 1N40.22)

ROTATIONAL DYNAMICS

Moment of Inertia

Disc 06-04

rolling bodies on incline

Rings, discs, spheres, and weighted discs are rolled down an incline. (PIRA # 1Q10.31)

Rotational Energy

Disc 06-01

angular acceleration machine

A weight over a pulley turns a bar with adjustable weights. On screen timer and protractor helps measurements. (PIRA # 1Q20.10)

Disc 06-02

bike wheel angular acceleration

Use a spring scale to apply a constant torque to a bike wheel and measure the angular acceleration. (PIRA # 1Q20.20)

Disc 06-05

spool on incline

A spool rolls down an incline on its central radius. (PIRA # 1Q20.30)

Disc 06-06

bike wheel on incline

A bike wheel rolls down an incline on its axle. The wheel can be pinned to the axle. (PIRA # 1Q20.35)

Disc 06-11

hinged stick and ball

A ball at the end of a hinged stick falls into a cup mounted on the stick. (PIRA # 1Q20.50)

Disc 06-10

penny drop stick

A horizontal meter stick, hinged at one end, is loaded with pennies and released. (PIRA # 1Q20.55)

Transfer of Angular Momentum

Disc 07-09

satellite derotator

Heavy weights fly off a rotating disc carrying away angular momentum. (PIRA # 1Q30.25)

Conservation of Angular Momentu

Disc 07-04

rotating stool with weights

A person sits on a rotating stool and moves weights in and out. (PIRA # 1Q40.10)

Disc 07-05

rotating stool and long bar

Sit on the stool and hold a long bar with weights on the ends. Rotate the bar and you will move in the opposite sense. (PIRA # 1Q40.15)

Disc 05-26

centrifugal governor

A model of a governor. (PIRA # 1Q40.23)

Disc 07-06

rotating stool and bicycle wheel

Invert a spinning bike wheel while sitting on a rotating stool. (PIRA # 1Q40.30)

Disc 07-02

train on a circular track

A wind up train rides on a track mounted on the rim of a horizontal bicycle wheel. (PIRA # 1Q40.40)

Disc 07-08

wheel and brake

A horizontal rotating bicycle wheel is braked to a large frame and the combined assembly rotates slower. (PIRA # 1Q40.45)

Disc 07-03

tail wags dog

Use a laser to magnify the motion of a pocket watch. (PIRA # 1Q40.50)

Disc 07-01

marbles and funnel

The angular speed of marbles increases as they approach the bottom of a large funnel. (PIRA # 1Q40.70)

Disc 15-07

Hero's engine

The flask rotates on a horizontal axis. (PIRA # 1Q40.80)

Disc 06-03

air rotator with deflectors

Run an air sprinkler, then mount deflectors to reverse the jet. (PIRA # 1Q40.82)

Gyros

Disc 07-11

gyro with adjustable weights

A small gyro is at the end of a pivoting rod with an adjustable counterweight. (PIRA # 1Q50.20)

Disc 07-12

bike wheels on gimbals

A bicycle wheel on gimbals has a long axle that can be weighted. (PIRA # 1Q50.22)

Disc 07-10

bike wheel precession

A spinning bicycle wheel is supported by a rope at one end of a long axle. (PIRA # 1Q50.23)

Disc 07-13

double bike wheel

The double bike wheel gyro precesses when both wheels rotate in the same direction. Has a nonstandard mount. (PIRA # 1Q50.25)

Disc 07-14

motorized gyroscope

A motorized gyro in gimbals. (PIRA # 1Q50.30)

Disc 07-07

gyroscopic stability

Move a gyro mounted on gimbals. (PIRA # 1Q50.35)

Disc 07-18

ship stabilizer

A motorized gyro is free to turn on a vertical axis when the ship model is rocked. (PIRA # 1Q50.72)

Rotational Stability

Disc 07-17

tippy top

The tippe top flips. (PIRA # 1Q60.30)

Disc 07-16

football spin

Spin a football on its side and it will rise up on its end. (PIRA # 1Q60.35)

Disc 07-20

stable and unstable axes of rotation

Toss a rectangular board into the air. (PIRA # 1Q60.40)

Disc 07-19

spinning rod and hoop of wire

Spin a hoop and long rod with a drill. (PIRA # 1Q60.51)

Disc 07-15

static/dynamic balance

A rotating system suspended by springs shows both the difference between static and dynamic balance. (PIRA # 1Q60.80)

PROPERTIES OF MATTER

Hooke's Law

Disc 08-01

Hooke's law

Add 10, 20, and 30 newtons to a large spring. (PIRA # 1R10.10)

Disc 08-02

springs in series and parallel

Pull on a spring, springs in series, and springs in parallel with a spring scale. Compare the force required to stretch each case 60 cm. (PIRA # 1R10.30)

Tensile and Compressive Stress

Disc 08-04

elastic limits

Stretch springs of copper and brass. The copper spring remains extended. (PIRA # 1R20.11)

Disc 08-05

Young's modulus

Hang weights from a wire. Use a laser and mirror optical lever to display the deflection. (PIRA # 1R20.15)

Disc 08-06

bending beams

Hang weights at the ends of extended beams. Use beams of different lengths and cross sections. (PIRA # 1R20.20)

Disc 08-08

bologna bottle

Pound a nail with a Bologna bottle, then add a carborundum crystal to shatter the bottle. (PIRA # 1R20.60)

Shear Stress

Disc 08-03

torsion rod

Rods of various materials and diameters are twisted in a torsion lathe. (PIRA # 1R30.40)

Coefficient of Restitution

Disc 05-04

coefficient of restitution

Drop glass, steel, rubber, brass, and lead balls onto a steel plate. (PIRA # 1R40.10)

Crystal Structure

Disc 16-15

crystal models

Show lattice models of sodium chloride, calcium carbonate, graphite, and diamond. (PIRA # 1R50.20)

Disc 16-16

faults in crystal

Show natural faults in a calcite crystal, then the single layer of small spheres model. (PIRA # 1R50.40)

FLUID MECHANICS

SURFACE TENSION

Force of Surface Tension

Disc 13-21

soap film pullup

A soap film pulls a sliding wire up a "U" shaped frame. (PIRA # 2A10.10)

Disc 13-20

floating metal sheet

Float a sheet of metal on the surface of distilled water and add weights until the metal sinks. (PIRA # 2A10.21)

Disc 13-19

surface tension disc

A flat glass disc on a soft spring is lowered onto the surface of distilled water and the extension upon pulling the disc off the water is noted. (PIRA # 2A10.33)

Disc 11-13

adhesion plates

Atmospheric pressure holds two plate glass panes together. (PIRA # 2A10.37)

Disc 13-23

two soap bubbles

The smaller soap film bubble blows up the larger one. (PIRA # 2A10.50)

Minumal Surface

Disc 13-24

minimim energy thread

Dip a frame with a loop of thread in soap, then pop the film in the center of the thread. (PIRA # 2A15.10)

Disc 13-22

soap film shapes

A pyramid, cube, and triangular prism. (PIRA # 2A15.20)

Capillary Action

Disc 13-26

capillary tubes

Fill a set of capillary tubes with water. (PIRA # 2A20.10)

Disc 13-25

capillary action

Touch the end of a small glass surface with a small glass tube and the water is drawn into the tube. (PIRA # 2A20.35)

Surface Tension Propulsion

STATICS OF FLUIDS

Static Presssure

Disc 12-04

pressure independent of direction

Membrane on a tube connected to a manometer. (PIRA # 2B20.10)

Disc 12-02

Pressure vs. depth

A pressure sensor is connected to a LED bar graph. (PIRA # 2B20.15)

Disc 12-03

pressure vs. depth in water and alco

The electronic pressure sensor and LED bar graph display are used first in water, then in alcohol. (PIRA # 2B20.16)

Disc 12-08

hydrostatic paradox

A glass plate is held against the large end of a truncated cone when it is placed under water. The plate drops away when placed against the small end. (PIRA # 2B20.34)

Disc 12-01

same level tubes

A commercial device. (PIRA # 2B20.40)

Disc 12-07

hydraulic press

Break a piece of wood in a hydraulic press. The press has a pressure gauge. (PIRA # 2B20.60)

Disc 11-17

air pressure lift

Lift a person supported by two hot water bottles by blowing them with the mouth. (PIRA # 2B20.65)

Disc 12-05

water/air compression

A syringe filled with air is compressed when a large weight is placed on it, but a water filled syringe does not compress. (PIRA # 2B20.71)

Atmospheric Pressure

Disc 11-16

barrel crush

Boil water in a 55 gal drum, seal, and cool. (PIRA # 2B30.20)

Disc 11-14

crush can with pump

A one gallon can is evacuated with a vacuum pump. (PIRA # 2B30.25)

Disc 11-12

Magdeburg hemispheres

An evacuated Magdeburg hemisphere set supports a large stack of weights. (PIRA # 2B30.30)

Disc 11-19

rubber sheet lifting chair

Lift a chair by placing a thin sheet of rubber with a handle on the seat and pulling up. (PIRA # 2B30.50)

Disc 11-18

inertia shingles

Break a wood stick protruding from under a paper. (PIRA # 2B30.60)

Disc 11-15

vacuum bazooka

Put a rubber ball in a tube, seal the ends, evacuate, and puncture the end with the ball. (PIRA # 2B30.70)

Measuring Pressure

Disc 11-10

barometer in vacuum

Evacuate a bell jar containing a barometer. (PIRA # 2B35.15)

Disc 11-11

aneroid barometer

Blow and suck on a chamber containing an aneroid barometer. (PIRA # 2B35.40)

Density and Buoyancy

Disc 12-11

buoyant force

A weight suspended from a spring scale is lowered into a beaker of water suspended from a spring scale. (PIRA # 2B40.14)

Disc 12-13

board and weights float

A board sinks equal amounts as equal weights are added. (PIRA # 2B40.18)

Disc 12-12

Archimedes' principle

Suspend a pail and weight from a spring scale, lower the weight into water, collect the overflow, pour it into the pail. (PIRA # 2B40.20)

Disc 12-17

battleship in bathtub

A block of wood is floated in rectangular container. (PIRA # 2B40.25)

Disc 12-22

Cartesian diver

A buoyant bottle in a water column. (PIRA # 2B40.30)

Disc 12-20

helium balloon in glass jar

A helium balloon floats in an inverted container but sinks when the container is filled with helium. (PIRA # 2B40.43)

Disc 12-21

helium balloon in liquid nitrogen

Cool a helium balloon to decrease its volume and it will no longer float. (PIRA # 2B40.44)

Disc 12-10

weight of air

A glass sphere is weighed on a pan balance, then evacuated and weighed again. (PIRA # 2B40.45)

Disc 12-06

water and mercury u-tube

Water and mercury rise to different heights in a "J" tube. (PIRA # 2B40.53)

Disc 12-18

buoyancy in various liquids

Iron, bakelite, and wood are dropped into a column containing mercury, carbon tetrachloride, and water. (PIRA # 2B40.54)

Disc 12-19

floating square bar

A long bar floats in one orientation in alcohol and switches to another orientation when water is added. (PIRA # 2B40.56)

Disc 12-15

density ball

A metal sphere barely floats in cold water and sinks in hot water. (PIRA # 2B40.59)

Disc 12-09

hydrometer

A hydrometer is placed in water, then in alcohol. (PIRA # 2B40.60)

Disc 12-14

different density woods

Float blocks of balsa, pine, and ironwood in water. (PIRA # 2B40.61)

Siphons, Fountains, Pumps

Disc 13-10

siphon

Start with two beakers half full of water and with a connecting hose full of water. Lift one beaker, then the other. (PIRA # 2B60.20)

DYNAMICS OF FLUIDS

Flow Rate

Disc 13-15

Toricelli's tank

Water streams from holes at different heights in a vertical glass tube. (PIRA # 2C10.10)

Disc 13-12

uniform pressure drop

Water flows in a horizontal glass tube with three pressure indicating standpipes fitted with wood floats. (PIRA # 2C10.20)

Disc 13-11

syringe water velocity

Squirt water out of a syringe. The water moves faster through the constriction. (PIRA # 2C10.26)

Bernoulli Force

Disc 13-13

Bernoulli's principle

Three pressure indicating manometers with bright wood floats are located at and on either side of a constriction in a horizontal tube with water flow. (PIRA # 2C20.10)

Disc 13-01

pitot tube

A pitot tube is connected to a water manometer and the air stream velocity is varied. Graphics. (PIRA # 2C20.25)

Disc 13-04

floating ball in air jet

A styrofoam ball is suspended in an air jet from a vacuum cleaner. (PIRA # 2C20.30)

Disc 13-05

suspended plate in air jet

Air blows radially out between two plates, supporting weights hung from the bottom plate. (PIRA # 2C20.40)

Disc 13-06

suspended parallel cards

Blow an air stream between two parallel cards on bifilar suspensions. (PIRA # 2C20.45)

Disc 13-03

curve balls

Throw a styrofoam ball with a throwing tube. Animation. (PIRA # 2C20.60)

Disc 13-02

Flettner rotator

A car with a spinning styrofoam cylinder moves perpendicular to an air stream. Animation. (PIRA # 2C20.80)

Viscosity

Disc 14-06

oil viscosity

Quickly invert tubes of oil and watch the bubbles rise to the top. (PIRA # 2C30.25)

Disc 14-02

viscous drag

Steel, glass, and lead balls are dropped in a tall cylinder filled with glycerine. (PIRA # 2C30.50)

Disc 14-03

ball drop

Several balls including styrofoam balls of three diameters are dropped four meters. Use stop frame and take data. (PIRA # 2C30.55)

Disc 14-01

air friction

Drop crumpled and flat sheets of paper. (PIRA # 2C30.65)

Turbulent and Streamline Flow

Vorticies

Disc 13-07

vortex cannon

Use a large barrel to generate a smoke ring. Blow out a candle with the vortex. Animation. (PIRA # 2C50.15)

Disc 13-09

tornado tube

Couple two soft drink bottles with the commercial tornado tube coupler and spin the top bottle so the water forms a vortex as it drains into the bottom bottle. (PIRA # 2C50.30)

Non Newtonian Fluids

Disc 12-16

density balls in beans

A ping pong ball in the middle of a beaker of beans will rise when the beaker is shaken. (PIRA # 2C60.20)

Disc 15-19

slime ball

A commercial product "Slime" flows like a liquid under normal conditions but bounces on impact. (PIRA # 2C60.35)

OSCILLATIONS AND WAVES

OSCILLATIONS

Pendula

Disc 08-15

4:1 pendula

4:1 pendula have 2:1 period. (PIRA # 3A10.14)

Disc 08-14

different mass pendula

Pendula of the same length and different mass oscillate together. (PIRA # 3A10.17)

Disc 08-13

torsion pendulum

Add weight to a torsion pendulum to decrease the period. (PIRA # 3A10.30)

Disc 08-19

variable angle pendulum

A physical pendulum is mounted on a bearing so the angle of the plane of oscillation can be changed. (PIRA # 3A10.40)

Physical Pendula

Disc 08-18

physical pendulum

Compare the period of a bar supported at the end with a simple pendulum of 2/3 length. (PIRA # 3A15.20)

Disc 08-16

hoops and arcs

A hoop oscillates with the same period as arcs corresponding to parts of the hoop. (PIRA # 3A15.40)

Disc 06-12

center of percussion

Hang a long metal bar by a string from one end. Strike the bar with a mallet at various points. (PIRA # 3A15.50)

Springs & Oscillators

Disc 08-11

mass on spring

Double the mass on the same spring. Try identical springs in parallel. (PIRA # 3A20.10)

Disc 08-12

air track simple harmonic motion

Place an air track glider between two springs. A video overlay overlay shows the sinusoidal path. (PIRA # 3A20.35)

Simple Harmonic Motion

Disc 08-20

circular motion vs. spring and weigh

Front on view of a marker on a disc and a mass on a spring. (PIRA # 3A40.10)

Disc 08-21

circular motion vs. pendulum

Front view of a marker on a disc and a pendulum. (PIRA # 3A40.20)

Disc 08-10

tuning fork with light

Attach a small light to a large slow fork and pan it by a video camera. A sine wave is visible by camera retention. (PIRA # 3A40.41)

Disc 08-22

phase shift

Shadow project two balls mounted on the edge of a disc. Vary the angle between the balls to vary the phase shift. (PIRA # 3A40.65)

Damped Oscillators

Driven Mechanical Resonance

Disc 09-02

resonant driven pendula

A massive pendulum drives three different length bifilar pendula. (PIRA # 3A60.31)

Disc 09-01

bowling ball pendulum resonance

Strike a bowling ball pendulum with random blows, then with blows at the normal frequency. (PIRA # 3A60.35)

Disc 09-03

driven spring weight

Drive a mass hanging from a spring. (PIRA # 3A60.43)

Disc 09-05

reed tachometer

A set of reeds is attached to a small unbalanced gyro. (PIRA # 3A60.50)

Coupled Oscillations

Disc 09-08

Wilberforce pendulum

Energy transfers between vertical and torsional modes. (PIRA # 3A70.10)

Disc 09-07

coupled pendula

Two physical pendula are coupled by a spring. (PIRA # 3A70.27)

Normal Modes

Lissajous Figures

Disc 08-26

Lissajous figures - scope

Use two independent generators to show Lissajous figures on a scope. (PIRA # 3A80.20)

Non-Linear Systems

Disc 08-17

pendulum with large amplitude

Vary the from 5 to 80 degrees. (PIRA # 3A95.33)

Disc 08-23

periodic non-simple harmonic motion

A large pendulum drives a restricted vertical pendulum. (PIRA # 3A95.38)

Disc 09-04

pump pendulum

Periodically pull on the string of a pendulum. (PIRA # 3A95.70)

WAVE MOTION

Transverse Pulses and Waves

Disc 09-09

wave on a rope

A long rope is attached to a wall. (PIRA # 3B10.10)

Disc 09-11

tension dependence of wave speed

Hold a rubber tube under different tensions and send a pulse along it. (PIRA # 3B10.15)

Disc 09-13

wave speed

Show the difference in wave speed and pulse shape on Shive machines with long and short rods. (PIRA # 3B10.16)

Disc 09-10

pulse on moving chain

A motor drives a large loop of chain suspended between horizontal pulleys. (PIRA # 3B10.25)

Disc 09-12

torsional waves

Show a torsional wave on a Shive wave machine. (PIRA # 3B10.30)

Disc 08-25

pendulum waves

The apparatus from AJP 59(2),186. (PIRA # 3B10.75)

Longitudinal Pulses and Waves

Disc 09-15

longitudinal slinky waves

Show longitudinal waves on a bifilar suspended slinky with paper flags every fifth coil. (PIRA # 3B20.10)

Disc 09-14

longitudinal wave model

The Pasco device. (PIRA # 3B20.30)

Standing Waves

Disc 09-27

three tensions standing waves

Three strings driven by the same driver have weights of 0.9:2:8 to produce the first, second, and third harmonics. (PIRA # 3B22.10)

Disc 09-28

rubber tube standing waves

A long rubber tube driven by a variable speed motor. (PIRA # 3B22.15)

Disc 09-26

standing waves

Drive the Shive wave machine by hand to produce standing waves. (PIRA # 3B22.30)

Disc 09-25

slinky standing waves

Drive a hanging slinky by hand to produce standing waves. (PIRA # 3B22.50)

Disc 09-24

longitudinal standing waves

Excite the Pasco longitudinal waves machine to get standing waves. (PIRA # 3B22.60)

Impedence and Dispersion

Disc 09-19

wave coupling

Shive wave machines with long and short rods are coupled abruptly or with a tapered section. (PIRA # 3B25.10)

Disc 09-17

reflection of waves

A pulse sent down a Shive wave machine reflects from either a fixed or free end. (PIRA # 3B25.20)

Disc 09-18

spring wave reflection

Reflections from a long horizontal brass spring with fixed and free ends. (PIRA # 3B25.25)

Disc 10-17

acoustic coupling

Sound a 2" loudspeaker alone and with an exponential horn. (PIRA # 3B25.35)

Compound Waves

Disc 09-16

wave superposition

Start positive pulses from each end of a Shive wave machine. (PIRA # 3B27.15)

Wave Properties of Sound

Disc 10-09

siren in vacuum

Place an electronic siren with a LED in series in a bell jar. (PIRA # 3B30.30)

Disc 10-14

sound in helium

Blow an organ pipe with air and helium, then talk with helium. (PIRA # 3B30.50)

Disc 10-13

sound velocity of different temperat

Blow two identical organ pipes from the same source, then heat the air going to one of the pipes with a Bunsen burner. (PIRA # 3B30.55)

Phase and Group Velocity

Reflection & Refraction (Sound)

Disc 09-20

refraction of water waves

Plane waves refract in a tank with deep and shallow sections. (PIRA # 3B35.60)

Transfer of Energy in Waves

Doppler Effect

Disc 10-21

doppler effect

Mount two speakers on a rotating frame and attach to an audio oscillator through slip rings. (PIRA # 3B40.10)

Shock Waves

Interference and Diffraction

Disc 09-21

single slit diffraction of water wav

Ripple tank single slit diffraction with varying slit and wavelength. (PIRA # 3B50.10)

Disc 09-22

double slit interference of water wa

Ripple tank double slit interference with varying wavelength and slit separation. (PIRA # 3B50.25)

Disc 09-23

Moire pattern

Two transparencies of equally spaced circles on the overhead. (PIRA # 3B50.40)

Inter. and Diff. of Sound

Disc 10-20

two speaker interference

Speakers in phase are mounted at the ends of a rotatable bar. (PIRA # 3B55.10)

Beats

Disc 10-18

tuning fork beats

Two tuning forks are on resonant boxes. Adjust the frequency of one to be slightly different. (PIRA # 3B60.10)

Disc 10-19

beats with speaker and oscilloscope

Two function generators are used to make beats that are displayed on a scope and amplified to a speaker. (PIRA # 3B60.20)

Coupled Resonators

ACOUSTICS

The Ear

Pitch

Disc 10-10

siren disc

A disc with concentric ring of equally spaced holes is spun by a motor and a jet of air is blown at each circle of holes. (PIRA # 3C20.30)

Disc 10-11

gear and card

Hold a card against gears on a common shaft with teeth in ratio of 4:5:6:8. (PIRA # 3C20.40)

Intensity and Attenuation

Architectural Acoustics

Wave Analysis and Synthesis

Disc 10-15

Fourier synthesizer

Use the Pasco Fourier synthesizer to demonstrate building square and triangle waves. (PIRA # 3C50.10)

Music Perception and the Voice

Disc 11-08

tuning forks on resonant boxes

Two tuning forks, two boxes. Show the box needs to be matched to the fork. (PIRA # 3C55.55)

Disc 10-16

vocal formants

Use an computer based real time spectrum analyzer to display vocal formants. (PIRA # 3C55.80)

INSTRUMENTS

Resonance in Strings

Disc 10-02

sonometer

An electromagnetic pickup is used to display the waveform of the sonometer string on an oscilloscope. (PIRA # 3D20.20)

Disc 10-01

guitar and scope

Show the output of an electric guitar on an oscilloscope. (PIRA # 3D20.21)

Stringed Instruments

Resonance Cavities

Disc 11-01

resonance tube with piston

Mount a microphone on a piston that slides in a glass tube and close the other end of the tube with a speaker. (PIRA # 3D30.15)

Disc 11-04

resonance tube 256/512

A tube is cut to length to resonate at 256 Hz when closed and 512 Hz when open. (PIRA # 3D30.20)

Disc 11-09

Helmholtz resonators

Two resonators are matched to two tuning forks. (PIRA # 3D30.40)

Disc 11-03

Kundt's tube

Stroke a rod to excite cork dust in a tube. (PIRA # 3D30.60)

Disc 11-07

singing pipes

Two metal tubes and a glass one. (PIRA # 3D30.70)

Air Column Instruments

Disc 11-02

resonance tubes (three lengths)

Blow air out of a flat nozzle across a set of three different length tubes. (PIRA # 3D32.10)

Disc 11-06

slide whistle

The variable length organ pipe. (PIRA # 3D32.15)

Disc 11-05

open and closed end pipes

Three organ pipes, open and closed. (PIRA # 3D32.25)

Resonance in Plates, Bars, Soli

Disc 10-07

xylophone bars

Use a microphone and oscilloscope to display the waveforms of various notes on a xylophone. (PIRA # 3D40.10)

Disc 10-05

rectangular bar oscillations

Strike a three foot rectangular bar on different faces and on the end. Listen to the different frequencies. (PIRA # 3D40.11)

Disc 10-06

high frequency metal bars

Hold a metal rod at the midpoint and strike at the end. Two rods an octave apart are shown. (PIRA # 3D40.12)

Disc 10-08

singing rods

Hold a long aluminum rod at the midpoint and stroke with rosined fingers. (PIRA # 3D40.20)

Disc 09-30

Chladni plates

A plate is driven by magnetostriction in the 10 to 30 Khz range. (PIRA # 3D40.30)

Disc 09-29

drumhead

A speaker drives a drumhead. (PIRA # 3D40.40)

Disc 09-06

glass breaking with sound

Large amplitude sound at the resonant frequency is directed at a beaker. (PIRA # 3D40.55)

Percussion Instruments

Tuning Forks

Disc 10-03

tuning fork

Use a microphone and oscilloscope to display the waveforms of 256, 512, and 1024 Hz tuning forks. (PIRA # 3D46.16)

Disc 10-04

adjustable tuning fork

Adjust masses on each tine of a large fork and show the waveform on an oscilloscope. Mistuned forks damp quickly. (PIRA # 3D46.22)

Electronic Instruments

SOUND REPRODUCTION

Loudspeakers

Microphones

Amplifiers

Recorders

THERMODYNAMICS

THERMAL PROPERTIES OF MATTER

Thermometry

Disc 24-17

liquid crystal sheets

Watch a liquid crystal thermometer change color. (PIRA # 4A10.50)

Liquid Expansion

Disc 14-13

thermal expansion of water

Fill a round bottomed flask with water, stick a slender tube in the neck, and heat with a burner. (PIRA # 4A20.10)

Disc 14-14

negative expansion coefficient of wa

Immerse a water thermometer in an ice bath (PIRA # 4A20.30)

Solid Expansion

Disc 14-08

bimetallic strip

Heat the commercial bimetallic strip in a flame. (PIRA # 4A30.10)

Disc 14-09

thermostat model

A bimetallic strip bends away from an electrical contact when heated turning off a light. (PIRA # 4A30.11)

Disc 14-11

thermal expansion

A brass plate with a hole is heated until it fits over a ball. (PIRA # 4A30.22)

Disc 14-10

pin breaker

Heat a rod to break a 1/8" diameter pin by expansion. (PIRA # 4A30.30)

Disc 14-07

thermal expansion of wire

A long iron wire with a small weight hanging at the midpoint is heated electrically. (PIRA # 4A30.60)

Properties of Materials at Low

Disc 08-09

elasticity of low temperature

Liquid nitrogen and a solder spring, rubber hose, etc. (PIRA # 4A40.15)

Disc 14-05

viscosity of alcohol at low temp

Cool alcohol with liquid nitrogen and pour through a cloth screen. (PIRA # 4A40.40)

Liquid Helium

HEAT AND THE FIRST LAW

Heat Capacity and Specific Heat

Disc 14-17

specific heat

Heat lead, aluminum, and steel to 100 C and then warm cool water. Show temp on LED bar graph. (PIRA # 4B10.10)

Disc 14-18

specific heat with rods and wax

Heat equal mass cylinders of aluminum, steel, and lead and let them melt a path through honeycomb. (PIRA # 4B10.30)

Convection

Disc 14-27

convection currents

An electric element heats water in the bottom of a projection cell. (PIRA # 4B20.40)

Conduction

Disc 14-21

thermal conductivity

Dip rods in wax, then watch as the wax melts off. Time Lapse. (PIRA # 4B30.12)

Radiation

Disc 22-04

heat focusing

Light a match using a heater and concave reflectors. Animation. (PIRA # 4B40.10)

Disc 14-25

radiation cube

Fill a Leslie cube with hot water and use a thermopile. to detect the radiation. (PIRA # 4B40.30)

Disc 14-24

two can radiation

Shiny and flat black cans filled with cool water warm up, cool off when filled with boiling water. (PIRA # 4B40.40)

Heat Transfer Applications

Disc 14-26

insulation (dewar flasks)

Hot water is placed in the four thermos bottles. (PIRA # 4B50.10)

Disc 14-19

boiling water in a paper cup

Burn one paper cup, boil water in another. (PIRA # 4B50.20)

Disc 14-20

water balloon heat capacity

Pop a balloon with a flame, then heat water in another balloon. (PIRA # 4B50.25)

Disc 14-22

Leyden frost phenomenom

Drop water on a hot plate, liquid nitrogen on the lecture table. (PIRA # 4B50.30)

Mechanical Equivalent of Heat

Disc 15-02

mechanical equivalent of heat

Flip a one meter tube containing lead shot ten times. A thermistor embedded in one end measures the temperature. (PIRA # 4B60.11)

Disc 15-01

drill and dowel

Chuck up a dowel in an electric drill and make smoke by drilling a board. (PIRA # 4B60.55)

Disc 15-08

cork popper

Water is heated in a stoppered tube by a motorized friction device until the cork blows. (PIRA # 4B60.70)

Adiabatic Processes

Disc 15-05

fire syringe

Compress air in a glass tube to light a tuft of cotton. Slow motion photography. (PIRA # 4B70.10)

Disc 15-04

adiabatic cooling

Pressurize a one gallon jar with a bicycle pump until the cork blows. Measure the temperature with a thermistor and computer. (PIRA # 4B70.25)

CHANGE OF STATE

PVT Surfaces

Phase Changes: Liquid-Solid

Disc 15-15

ice bomb

An ice bomb is placed in a liquid nitrogen bath. (PIRA # 4C20.20)

Disc 15-16

regelation

A mass hanging from a loop of thin stainless steel wire cuts through a block of ice. (PIRA # 4C20.30)

Disc 15-03

CO2 expansion cooling

Shoot off a fire extinguisher at a test tube of water, freezing the water. (PIRA # 4C20.45)

Phase Changes: Liquid-Gas

Disc 15-10

boil water under reduced pressure

Boil water in a r.b. flask with a dimple in the bottom, remove from heat, stopper, invert and add ice to the dimple. (PIRA # 4C30.10)

Disc 15-17

helium and CO2 balloons in liquid N2

Helium and CO2 balloons are immersed in liquid nitrogen. Cut open the CO2 balloon to show solid carbon dioxide. (PIRA # 4C30.30)

Disc 15-09

liquid nitrogen in balloon

Pour some liquid nitrogen in a small flask and cap with a balloon. (PIRA # 4C30.35)

Cooling by Evaporation

Disc 15-14

cryophorus

Place a cryophorus in liquid nitrogen. (PIRA # 4C31.10)

Disc 15-13

freezing by boiling

Evacuate a chamber containing a small amount of water. (PIRA # 4C31.20)

Disc 15-12

drinking bird

Standard drinking bird. Includes animation. (PIRA # 4C31.30)

Dew Point and Humidity

Vapor Pressure

Sublimation

Disc 15-18

sublimation of CO2

Small solid carbon dioxide flakes are generated by cooling a CO2 balloon in liquid nitrogen. (PIRA # 4C40.10)

Phase Changes: Solid - Solid

Critical Point

Disc 15-11

CO2 critical point

Warm a tube containing liquid CO2. The critical point is 73 atmospheres at 31.6 C. (PIRA # 4C50.10)

KINETIC THEORY

Brownian Motion

Disc 16-07

brownian motion

A smoke cell is viewed under 100X magnification. (PIRA # 4D10.10)

Disc 16-08

Brownian motion simulation

A large disc is placed in with small ball bearings in the shaker frame on the overhead projector. (PIRA # 4D10.20)

Mean Free Path

Disc 14-23

radiometer

The radiometer and a lamp. (PIRA # 4D20.10)

Kinetic Motion

Disc 16-05

equipartition of energy simulation

Use different size balls in the shaker frame on the overhead. (PIRA # 4D30.21)

Disc 16-04

pressure vs. volume simulation

Change the size of the entrained area of the shaker frame on the overhead projector. (PIRA # 4D30.22)

Disc 16-13

free expansion simulation

Balls are initially constrained to one half of the shaker frame and then the bar is lifted. (PIRA # 4D30.23)

Disc 16-03

temperature increase simulation

A shaker frame on the overhead projector is shown with different shaking rates. (PIRA # 4D30.24)

Disc 16-06

mercury kinetic theory

Glass chips float on a pool of mercury in an evacuated tube. Heat the mercury and the chips dance in the mercury vapor. (PIRA # 4D30.40)

Disc 14-04

gas viscosity change with temp

Heat the gas flowing to one of two identical burners and the flame decreases. (PIRA # 4D30.60)

Molecular Dimensions

Diffusion & Osmosis

Disc 16-09

diffusion

Methane and helium are diffused through a porous clay jar. A glass tube extending down into a jar of water bubbles as an indicator. (PIRA # 4D50.20)

Disc 16-11

bromine diffusion

Glass tubes containing bromine and bromine/air are cooled in liquid nitrogen and allowed to warm back up to show diffusion. (PIRA # 4D50.45)

Disc 16-10

diffusion simulation

A bar across the shaker frame on the overhead projector has a small hole that allows small but not larger balls to pass. (PIRA # 4D50.80)

GAS LAW

Constant Pressure

Disc 14-12

thermal expansion of air

Hold the inverted flask of Galileo's thermometer with the hands to heat the entrained air and force the water in the tube down. (PIRA # 4E10.11)

Constant Temperature

Disc 16-01

pressure vs. volume

A pressure gauge is mounted on a glass syringe. (PIRA # 4E20.15)

Constant Volume

Disc 16-02

pressure vs. temperature

A constant volume sphere with a pressure gauge is shown at room temperature and immersed in ice water and boiling water baths. (PIRA # 4E30.10)

ENTROPY AND THE SECOND LAW

Entropy

Disc 13-08

un-mixing

Glycerine between two concentric cylinders. Animation. (PIRA # 4F10.10)

Disc 14-15

dust explosion

Blow lycopodium powder into a can containing a candle. (PIRA # 4F10.40)

Heat Cycles

Disc 15-06

Stirling engine

Shows the standard Stirling engine, includes good animation. (PIRA # 4F30.10)

ELECTRICITY AND MAGNETISM

ELECTROSTATICS

Producing Static Charge

Disc 16-21

electrostatic rods

Rub acrylic and rubber rods with wool and place on a pivot. Graphic overlays show charges. (PIRA # 5A10.10)

Disc 17-03

electrophorus

Repeat charging a metal plate many times. Animation sequence shows movement of charges. (PIRA # 5A10.20)

Disc 16-22

electrostatic rod and cloth

Rub a rod with a cloth, place on a pivot, show attraction between rod and cloth. (PIRA # 5A10.37)

Coulomb's Law

Disc 16-23

electrostatic ping-pong deflection

Attraction and repulsion between charged conductive ping pong balls. (PIRA # 5A20.25)

Electrostatic Meters

Conductors and Insulators

Disc 16-25

conductors and insulators

Aluminum and acrylic rods are mounted on a Braun electroscope. Bring a charged rod close to each rod. (PIRA # 5A30.15)

Induced Charge

Disc 17-01

electrostatic induction

Use two metal spheres, a charged rod, and an electroscope. Animation shows charges. (PIRA # 5A40.10)

Disc 17-06

wooden needle

The "needle" is a six foot 2X4. (PIRA # 5A40.30)

Disc 17-02

metal rod attraction

Place a metal rod on a pivot and show attraction to both positive and negative charged rods. (PIRA # 5A40.35)

Disc 17-05

Kelvin water dropper

A Kelvin water dropper discharges a small neon lamp. Animation sequence shows principles of operation. (PIRA # 5A40.70)

Electrostatic Machines

Disc 17-04

induction generator

Shows Wimshurst machine. Animation sequence shows principles of operation. (PIRA # 5A50.10)

Disc 17-07

Van de Graaff generator

Shows a Van de Graaff with paper streamers, then a long animated sequence on the principles of operation. (PIRA # 5A50.31)

ELECTRIC FIELDS AND POTENTIAL

Electric Field

Disc 17-08

Van de Graaff with streamers

Show Van de Graaff with paper streamers, then hair on end. (PIRA # 5B10.15)

Disc 16-24

electrostatic ping-pong balls

Conductive ping pong balls bounce between horizontal plates charged with a Wimshurst. (PIRA # 5B10.30)

Disc 17-10

electric field

A pan on the overhead projector contains particles in a liquid that align with the electric field. (PIRA # 5B10.40)

Gauss' Law

Disc 17-15

Faraday ice pail

Charge a bucket with a Wimshurst and transfer charge from the inside and outside of the bucket to an electroscope. (PIRA # 5B20.10)

Disc 17-14

Faraday cage

Bring a charged rod near a Braun electroscope, then cover the electroscope with a wire mesh cage and repeat. (PIRA # 5B20.30)

Disc 21-17

radio in Faraday cage

Place a wire mesh cage over a radio. (PIRA # 5B20.35)

Electrostatic Potential

Disc 17-11

lightning rod

Sparks discharge from a large ball suspended over a model house with a small ball in the chimney until a point is raised above the small ball. (PIRA # 5B30.30)

Disc 17-09

Van de Graaff and wand

With paper streamers as a field indicator, bring a ball and point close to the Van de Graaff. (PIRA # 5B30.35)

Disc 17-13

point and candle

Attach a sharp point to one terminal of a Toepler-Holtz generator and point it at a candle flame. (PIRA # 5B30.40)

Disc 17-12

pin wheel

Place a pinwheel on a Van de Graaff generator. (PIRA # 5B30.50)

Disc 17-16

smoke precipitation

Attach a Wimshurst to terminals at each end of a glass tube filled with smoke. (PIRA # 5B30.60)

CAPACITANCE

Capacitors

Disc 18-19

parallel plate capacitor

Charge parallel plates with a rod, watch the electroscope as the distance between the plates is changed. Animation sequence. (PIRA # 5C10.20)

Disc 18-22

battery and separable capacitor

Charge a parallel plate capacitor to 300 V, then move the plates apart until an electroscope deflects. (PIRA # 5C10.21)

Disc 18-21

rotary capacitor

Charge a large rotary capacitor with a rod and watch an electroscope as the overlap is changed. (PIRA # 5C10.35)

Dielectric

Disc 18-20

parallel plate capacitor dielectrics

Charge a parallel plate capacitor with a rod, insert dielectrics and observe the electroscope. Animation. (PIRA # 5C20.10)

Disc 18-24

force on a dielectric

A counterbalanced acrylic dielectric is pulled down between parallel plates when they are charged with a small Wimshurst generator. (PIRA # 5C20.20)

Disc 18-25

dissectible capacitor

Charge a capacitor and show the discharge, then charge again and take it apart. Handle it, try to discharge it, reassemble it, and discharge it. (PIRA # 5C20.30)

Energy Stored in a Capacitor

Disc 18-18

Leyden jars on Toepler-Holtz

The Topler-Holtz produces weak sparks without the Leyden jars and strong less frequent sparks with the jars connected. (PIRA # 5C30.10)

Disc 18-26

grounded Leyden jar

Charge a capacitor with a Wimshurst, ground each side separately, spark to show the charge is still there. (PIRA # 5C30.15)

Disc 18-23

exploding capacitor

Four 1000 microF capacitors are charged to 400 V storing about 320 Joules. Short them with a metal bar. (PIRA # 5C30.20)

Disc 18-27

series/parallel capacitors

Charge a single capacitor, two series capacitors, and two parallel capacitors to the same potential and discharge through a ballistic galvanometer. (PIRA # 5C30.42)

RESISTANCE

Resistance Characteristics

Disc 17-18

resistance wires

Place 6V across a set of wires of different lengths and/or diameters and measure the currents. (PIRA # 5D10.20)

Disc 17-22

electron motion model

Ball bearings are simultaneously rolled down two ramps, one with pegs and one without. (PIRA # 5D10.40)

Resistivity and Temperature

Disc 17-21

cooled wire

A copper coil in series with a battery and lamp is immersed in liquid nitrogen. (PIRA # 5D20.10)

Disc 17-20

heated wire

Heat a coil of iron wire in series with a battery and a lamp. (PIRA # 5D20.20)

Disc 18-09

carbon and tungsten lamps

Plot current vs. voltage for carbon and tungsten lamps. (PIRA # 5D20.30)

Disc 16-17

thermistor

Show the resistance of a thermistor placed in an ice water bath. (PIRA # 5D20.50)

Conduction in Solutions

Disc 18-13

conductivity of solutions

Two electrodes in series with a 110 V lamp are dipped into distilled water, salt water, a sugar solution, a vinegar solution, and tap water. (PIRA # 5D30.10)

Conduction in Gases

Disc 25-08

Jacob's ladder

Apply high voltage AC to rabbit ears. (PIRA # 5D40.10)

Disc 25-03

thermionic emission

A commercial tube. Apply 90 V forward and reverse and monitor the current. (PIRA # 5D40.42)

Disc 18-08

neon bulb resistivity

A neon lamp lights at about 80 V and shuts off at about 60 V. (PIRA # 5D40.50)

Disc 24-20

x-ray ionization

Discharge an electroscope with x-rays. (PIRA # 5D40.80)

ELECTROMOTIVE FORCE AND CURRENT

Electrolysis

Disc 18-16

electrolysis

The standard commercial electrolysis apparatus. (PIRA # 5E20.10)

Plating

Disc 18-17

electroplating

Copper is plated onto a carbon electrode in a copper sulfate bath. (PIRA # 5E30.20)

Disc 18-15

pickle frying

Apply high voltage across a pickle and it lights at one end. (PIRA # 5E30.30)

Cells and Batteries

Disc 18-14

battery effect

Combinations of copper, lead, zinc, and iron are dipped into a dilute sulfuric acid solution. (PIRA # 5E40.10)

Disc 18-03

internal resistance of batteries

Measure similar no load voltage on identical looking batteries and then apply a load to each and show the difference in voltage between a good and weak battery. (PIRA # 5E40.75)

Thermoelectricity

Disc 16-20

thermocouple

Place a twisted wire thermocouple in a flame and observe the current on a lecture table galvanometer. (PIRA # 5E50.10)

Disc 16-18

thermoelectric magnet

Heat and cool opposite sides of a large thermocouple. Suspend a large weight from an electromagnet powered by the thermocouple current. (PIRA # 5E50.30)

Disc 16-19

thermoelectric heat pump

Mount aluminum blocks with digital thermometers on either side of a Peltier device. Run the current both ways. (PIRA # 5E50.60)

Piezoelectricity

Disc 16-26

piezoelectric sparker

Attach the commercial piezoelectric sparker to Braun electroscope. (PIRA # 5E60.20)

DC CIRCUITS

Ohm's Law

Disc 17-19

Ohm's law

Place 2, 4, and 6 V across a resistor and measure the current, then graph. (PIRA # 5F10.10)

Disc 18-01

voltage drop along wire

Measure the voltage at six points on a long resistance wire. (PIRA # 5F10.20)

Power and Energy

Disc 18-07

hot dog frying

Apply 110 V through a hot dog and cook it. (PIRA # 5F15.20)

Disc 18-05

voltage drops in house wires

Two resistance wires substituting for house wiring glow when they power a load of lamps and heaters. (PIRA # 5F15.40)

Disc 18-06

I2R losses

Copper and nichrome wires in series show different amounts of heating due to current. A paper rider on the nichrome wire burns. (PIRA # 5F15.45)

Circuit Analysis

Disc 18-02

sum of IR drops

Measure the voltages across three resistors and a battery in a series circuit. (PIRA # 5F20.10)

Disc 17-27

conservation of current

Measure the currents entering and leaving a node. (PIRA # 5F20.16)

Disc 17-25

wheatstone bridge

Three 110 V lamps and a rheostat make up the diamond of a Wheatstone bridge and a small lamp serves as an indicator. (PIRA # 5F20.45)

Disc 17-24

series/parallel light bulbs

Three 110 V lamps are wired in series and three are wired in parallel. (PIRA # 5F20.50)

Disc 17-23

series/parallel resistors

Measure the current flowing through a wire resistor with 6 V applied and then series and parallel combinations. (PIRA # 5F20.55)

RC Circuits

Disc 18-28

RC charging curve

Show charging and discharging a RC circuit with a battery on an oscilloscope. (PIRA # 5F30.20)

Disc 18-29

relaxation oscillator

An RC neon light relaxation oscillator. (PIRA # 5F30.60)

Instruments

Disc 17-26

galvanometer as voltmeter and ammete

A galvanometer is used with shunt and series resistors. (PIRA # 5F40.20)

Disc 18-04

loading by a voltmeter

Measure the voltage across a high resistance circuit with high and low impedance voltmeters. (PIRA # 5F40.21)

MAGNETIC MATERIALS

Magnets

Disc 19-02

lodestone

A large lodestone is suspended in a cradle with the south pole painted white. A bar magnet is used to show attraction and repulsion. (PIRA # 5G10.16)

Disc 19-05

broken magnet

A broken magnet still exhibits north and south poles. (PIRA # 5G10.20)

Disc 19-06

lowest energy configuration

Magnets held vertically in corks are placed in a dish of water. When a coil around the dish is energized, the magnets move to the lowest energy configuration. (PIRA # 5G10.50)

Magnet Domains & Magnetization

Disc 19-19

Barkhausen effect

Pulses from moving a magnet near a coil wrapped around a soft iron core are amplified. (PIRA # 5G20.10)

Disc 19-16

magnetic domain model

A set of compass needles on pins. (PIRA # 5G20.30)

Disc 19-21

permalloy in earth's field

A small strip of iron sticks to a permalloy rod when it is held in the direction of the Earth's field. (PIRA # 5G20.55)

Disc 19-17

magnetizing iron

Place an iron bar in a solenoid and pulse a large current. (PIRA # 5G20.60)

Disc 19-15

magnitizing iron by contact

Stroke a nail on a permanent magnet and it will pick up iron filings. (PIRA # 5G20.61)

Disc 19-18

demagnitizing iron by hammering

Magnetize an iron bar in a solenoid, then pound it to demagnetize. (PIRA # 5G20.62)

Disc 19-12

electromagnet with 1.5 V battery

A magnet powered by a 1.5 V battery lifts a large weight. (PIRA # 5G20.70)

Disc 19-11

large electromagnet

This magnet is made with 3000 turns and carries 25 amps. (PIRA # 5G20.72)

Paramagnetism and Diamagnetism

Disc 19-22

paramagnetism and diamagnetism

Samples of bismuth and copper sulfate are suspended by threads. A large horseshoe magnet attracts the copper sulfate and repels the bismuth. (PIRA # 5G30.15)

Hysteresis

Disc 20-28

hysteresis curve

The Leybold setup shown on a scope. (PIRA # 5G40.10)

Disc 20-29

hysteresis waste heat

Water is boiled by magnetic hysteresis waste heat. (PIRA # 5G40.50)

Magnetostriction and Magnetores

Temperature and Magnetism

Disc 19-24

Curie Nickel

A Canadian nickel is attracted to a magnet until it is heated with a torch. (PIRA # 5G50.15)

Disc 19-25

Curie temperature wheel

A rim of nickel on a wheel is heated just above the point where the rim passes through the gap of a magnet. (PIRA # 5G50.20)

Disc 19-23

dysprosium in liquid nitrogen

A piece of dysprosium is attracted to a magnet when cooled to liquid nitrogen temperatures but drops away when it warms up. (PIRA # 5G50.25)

Disc 16-14

superconductors

Place a small powerful magnet over a disc of superconducting material cooled to liquid nitrogen temperature. (PIRA # 5G50.50)

MAGNETIC FIELDS AND FORCES

Magnetic Fields

Disc 19-03

dip needle

Turn a compass on its side. Animation. (PIRA # 5H10.15)

Disc 19-08

Oersted's needle

Hold a current carrying wire over a bar magnet on a pivot and the magnet moves perpendicular to the wire. (PIRA # 5H10.20)

Disc 19-04

magnetic fields around bar magnets

Sprinkle iron filings on a glass sheet covering a bar magnet. (PIRA # 5H10.30)

Disc 19-20

magnetic shielding

Slide sheets of copper, aluminum, and iron between an electromagnet and an acrylic sheet separating nails from the magnet. (PIRA # 5H10.61)

Fields and Currents

Disc 19-09

magnetic fields around currents

Iron filings around a current carrying wire, loop, coil, and solenoid. (PIRA # 5H15.10)

Disc 19-07

right hand rule

Move a compass around a vertical wire with a current, reverse the current. Animation of the right hand. (PIRA # 5H15.13)

Disc 19-14

Biot-Savart law

Animation. (PIRA # 5H15.15)

Forces on Magnets

Disc 19-01

magnetic attraction/repulsion

One magnet is placed on a pivot, the other is used to attract or repel the first. (PIRA # 5H20.10)

Magnet/Electromagnet Interact.

Disc 19-10

solenoid bar magnet

A suspended solenoid reacts with a bar magnet only when the current is on. (PIRA # 5H25.10)

Force on Moving Charges

Disc 20-03

deflected electron beam

A thin electron beam made visible by a fluorescent screen is bent when a magnet is brought near. (PIRA # 5H30.15)

Disc 20-04

fine beam tube

A fine beam tube between Helmholtz coils. (PIRA # 5H30.25)

Disc 20-06

ion motor

Cork dust shows the motion of copper sulfate an ion motor. Animation. (PIRA # 5H30.55)

Force on Current in Wires

Disc 19-13

pinch wires

Six wires in parallel attract when current passes through each in the same direction. Then sets of three wires each have current flowing in opposite directions. (PIRA # 5H40.20)

Disc 20-07

AC/DC magnetic contrast

A magnet is brought near a carbon lamp filament powered by DC, then AC. (PIRA # 5H40.23)

Disc 20-01

jumping wire coil

Run twenty amps through a wire in a horseshoe magnet. (PIRA # 5H40.35)

Disc 20-05

Barlow's wheel

Current flows radially in a disc mounted between the poles of a magnet. (PIRA # 5H40.50)

Disc 20-02

Ampere's frame

A magnet is brought near and rotates a large current carrying loop. (PIRA # 5H40.70)

Torques on Coils

Disc 20-08

D'Arsonval meter

A large open galvanometer. (PIRA # 5H50.10)

INDUCTANCE

Self Inductance

Disc 21-01

inductance spark

Disconnect a 6 V battery from a 2000 turn coil to get a spark, enhance with an iron core. (PIRA # 5J10.20)

LR Circuits

Disc 21-03

lamps in parallel with solenoid

Apply 110 V to a large solenoid with incandescent and neon lamps in parallel. The neon lamp flashes on the opposite side on discharge. (PIRA # 5J20.20)

RLC Circuits - DC

Disc 21-05

damped LRC oscillation

Discharge a capacitor through a series LRC circuit. Vary the capacitance and resistance. (PIRA # 5J30.11)

ELECTROMAGNETIC INDUCTION

Induced Currents and Forces

Disc 20-11

Wire and magnet

Move a wire connected to a galvanometer in and out of a horseshoe magnet. (PIRA # 5K10.15)

Disc 20-12

10/20/40 coils with magnet

Coils of 10, 20, and 40 turns are attached to a galvanometer. (PIRA # 5K10.21)

Disc 20-17

inductive coil with lamp

Swing a coil attached to a lamp through the gap of a horseshoe magnet. (PIRA # 5K10.25)

Disc 20-20

two coils

Changing the current in one coil causes a current in the other. (PIRA # 5K10.30)

Disc 20-16

current-coupled pendula

Interconnected coils are hung as pendula in the gaps of two horseshoe magnets. Start one swinging and the other swings. (PIRA # 5K10.48)

Disc 20-13

Earth coil

Flip the standard Earth coil attached to a galvanometer. (PIRA # 5K10.60)

Disc 20-27

electromagnetic can breaker

A large pulse of induced current in a soda can blows it apart. (PIRA # 5K10.90)

Eddy Currents

Disc 20-24

Eddy current pendulum

Copper, wood, etc. bobs are swung in a large permanent magnet. (PIRA # 5K20.10)

Disc 20-26

Eddy current tubes

Drop a magnet and a dummy in glass and aluminum tubes, then switch. (PIRA # 5K20.25)

Disc 20-19

Faraday repulsion coil

Thrust the pole of a magnet in and out of a copper ring of a bifilar suspension. (PIRA # 5K20.26)

Disc 20-18

Thompson's flying ring

A copper ring levitates, an aluminum ring flies off, a slit ring does nothing, and a cooled ring flies higher. (PIRA # 5K20.30)

Disc 20-25

Arago's disk

A bar magnet suspended above a spinning aluminum disc will start to rotate. (PIRA # 5K20.42)

Transformers

Disc 20-23

transformers

Many variations with the Leybold transformer. (PIRA # 5K30.20)

Disc 20-22

vertical primary and secondary coils

The vertical transformer is used with two coils, one with many turns powers a 110 V lamp, and the other with fewer turns powers a flashlight lamp. (PIRA # 5K30.30)

Motors and Generators

Disc 20-09

DC motor

A large model DC motor. (PIRA # 5K40.10)

Disc 20-14

Faraday disc

Spin a copper disc between the poles of a horseshoe magnet with brushes at the center and edge of the disc connected to a galvanometer. (PIRA # 5K40.15)

Disc 20-15

ac/dc generator

A large AC/DC generator with slip and split rings. (PIRA # 5K40.40)

Disc 03-16

hand cranked generator

A hand cranked generator slows down in five seconds from internal friction or in one second while lighting a lamp. (PIRA # 5K40.80)

Disc 03-17

generator driven by falling weight

A weight on a string wrapped around the shaft of a generator falls more slowly when there is an electrical load on the generator. (PIRA # 5K40.85)

AC CIRCUITS

Impedence

Disc 21-02

inductor with lamp on AC

Place a large coil in series with a light bulb, then insert an iron core in the coil and the light bulb dims. (PIRA # 5L10.10)

LCR Circuits - AC

Disc 21-04

driven LRC circuit

The voltage and current across the capacitor, inductor, resistor, and supply are shown in succession on an oscilloscope. (PIRA # 5L20.18)

Filters and Rectifiers

Disc 18-11

rectifier circuit

Diodes in a Wheatstone bridge configuration followed by two low pass filters. (PIRA # 5L30.10)

SEMICONDUCTORS AND TUBES

Semiconductors

Disc 20-10

Hall effect

A Hall effect probe in a magnet, animation. (PIRA # 5M10.10)

Disc 18-10

diode

Positive and negative voltages are applied to a lamp in series with a diode. (PIRA # 5M10.50)

Disc 18-12

transistor amplifier

A transistor circuit board shows simple amplification. (PIRA # 5M10.90)

Tubes

ELECTROMAGNETIC RADIATION

Transmission Lines and Antennas

Disc 21-13

Lecher wires

Standing waves are generated on parallel wires by a radio transmitter. An incandescent bulb placed across the wires indicates voltage maxima. (PIRA # 5N10.50)

Disc 21-15

microwave standing waves

Standing waves are set up between a microwave transmitter and a metal sheet. The receiver is moved between the two and the signal strength is displayed on a LED bar graph. (PIRA # 5N10.55)

Disc 21-11

radio waves

Show radiation with a 100 MHz dipole transmitter and hand held dipole receiver with a flashlight bulb detector. (PIRA # 5N10.60)

Tesla Coil

Disc 20-21

induction coil

A large induction coil, explained with the aid of animation. (PIRA # 5N20.10)

Disc 21-06

Tesla coil

Light a fluorescent tube at a distance, show the skin effect. (PIRA # 5N20.50)

Electromagnetic Spectrum

Disc 21-14

microwave unit

A LED bar graph indicates signal strength as a microwave transmitter is rotated around a receiver and as the beam is blocked by a metal sheet. (PIRA # 5N30.30)

Disc 21-16

microwave absorption

Place dry and wet cloths in the microwave beam. (PIRA # 5N30.50)

GEOMETRICAL OPTICS

Disc 21-07

light in a vacuum

Place a flashing light in the bell jar to emphasize the point. (PIRA # 6A02.10)

Disc 21-08

straight line propagation

Cast shadows with a point source. (PIRA # 6A02.15)

Reflection From Flat Surfaces

Disc 21-20

angle of incidence, reflection

Aim a beam of light at a mirror at the center of a disc, rotate the disc. (PIRA # 6A10.11)

Disc 21-18

microwave reflection

Reflect a microwave beam off a metal plate into a receiver. (PIRA # 6A10.18)

Disc 21-19

diffuse/specular reflection

Show a beam on light reflecting off a mirror on an optics board. Replace the mirror with a sheet of paper. (PIRA # 6A10.20)

Disc 21-24

corner reflection

Look at your image in a corner cube. (PIRA # 6A10.30)

Disc 21-22

parity reversal in a mirror

View a Cartesian coordinate system in a mirror. (PIRA # 6A10.37)

Disc 21-23

hinged mirrors

Mirrors angled at 60 degrees give one object and five images arranged in a hexagon. (PIRA # 6A10.40)

Disc 21-25

barbershop mirrors

Place objects between parallel mirrors and view them over one of the mirrors. (PIRA # 6A10.45)

Disc 21-21

location of image

Place a sheet of glass between a burning candle and a glass of water so the image of the candle appears in the glass. (PIRA # 6A10.60)

Disc 21-26

Mirror Box

Two people look into opposite ends of a box containing a half silvered mirror in the center. As the light on one end is dimmed, the light on the other brightens, causing metamorphosis. (PIRA # 6A10.65)

Reflection from Curved Surfaces

Disc 22-01

concave and convex mirrors

Shine parallel beams at convex and concave mirrors. Use a thread screen for display. (PIRA # 6A20.10)

Disc 22-02

spherical abberation in a mirror

Shine parallel rays at spherical and parabolic mirror elements, noting the difference in aberration. (PIRA # 6A20.20)

Disc 22-05

large concave mirror

Hold a candle and other objects at the center of curvature of a large convex mirror. (PIRA # 6A20.31)

Disc 22-03

energy at a focal point

Remove the projection head of an overhead projector and hold a piece of paper at the focal point until it bursts into flame. (PIRA # 6A20.60)

Refractive Index

Disc 22-10

disappearing eye dropper

Place an eyedropper in a liquid with an index of refraction matched to the glass. (PIRA # 6A40.30)

Refraction at Flat Surfaces

Disc 22-06

refraction/reflection from plastic

Rotate a rectangle of plastic in a single beam of light. (PIRA # 6A42.12)