Physics Lecture Demonstrations

Revised Mon Dec 11 14:56:07 2017


Table of Contents


The Physics Lecture Demonstrations in the Department of Physics and Astronomy at Johns Hopkins University are listed in the table below according to the topic area that best describes the physical concept(s) illustrated. The listing broadly follows the PIRA demonstration classification scheme order. For each topic, there follows a list of one or more demonstrations. These are listed by number and name, and are followed by a short description of the demonstration. An underlined demo name is a hyperlink to additional information about that demonstration. A more detailed listing of demonstrations is available upon request.


 

Mechanics

Measurement

Basic Units

M-a1d

Standard Mass

Show and tell about a 1-kg standard mass.

M-a1a

Meter Standard

A replica of the platinum-iridium bar in Paris that was the international standard for length before 1960.

M-a1b

One Nanosecond Bar

A piece of plastic cut to a 1 ns length and imprinted "one nanosecond." Ruler shown for comparison.

M-a1c

One Mole Bars

Set containing one mole each of iron, copper, zinc, and aluminum.

Error and Accuracy

M-a2a

Probability Board

Balls roll down a nail board into parallel chutes forming a Gaussian distribution.

Coordinate Systems

M-a3a

3-D XYZ axes

A simple 3-D XYZ Coordinate System

Vectors

M-a4b

NTNU Vector Addition Simulation

A 2-D and 3-D vector simulation: http://www.phy.ntnu.edu.tw/java/vector/vector.html

M-a4c

PhET Vector Addition Simulation

Colorado PhET 2-D vector simulation: http://www.colorado.edu/physics/phet/simulations/vectormath/vectorMath.swf

M-a4a

Magnetic Blackboard Vectors

A set of magnet-backed vectors of lengths 3, 4, and 5 used to show vector addition on the blackboard.

Math Topics

M-a5a

Rotation with Rotary Motion Sensor

Use a rotary motion sensor to show angular displacement and angular velocity vs. time on the computer.

M-a4e

Dirac String Trick

Strings become untangle-able when this device is rotated through 720 degrees but not 360 degrees

M-a4d

Klein Bottle

Show and Tell Item: Klein Bottle

Scaling

M-a6a

Movie--Powers of Ten

"Powers of Ten" is a 9 minute film spanning scales from the edge of the universe to the sub-atomic. URL: https://www.youtube.com/watch?v=0fKBhvDjuy0

M-a6b

Movie--Cosmic Voyage

"Cosmic Voyage" is a glitzy 35 minute film with an 8:45 minute powers-of-ten cosmic zoom sequence, plus descriptions and visualizations of varied scientific theories exploring the origin of man. Available on DVD only.

M-a6d

Movie: Galaxy

2 min. 50 sec. animated musical video, based on NASA photos, about the galaxy and man's small place in it. http://dingo.care2.com/cards/flash/5409/galaxy.swf

M-a6e

Sumulation - Scale of Universe

Interactive Scale of the Universe Tool in Adobe Flash

M-a6c

Diluting dye solution - Powers of Ten

Ten ml of a strong dye solution is transferred to a 90ml solution of water; 10 ml of the result is transferred to another 90 ml of water, ad infinitum to show "one millionth" and "one billionth" and so on.

Motion in One Dimension

Position, Velocity, Acceleration

M-c1d

Motion Detector and Student

An ultrasonic motion detector generates a real-time graph of displacement (and/or veloctiy and/or acceleration) versus time as a student walks back and forth in front of the detector.

Velocity

M-c1a

Addition of Velocities--Tank and Sheet

A battery powered tank runs at constant speed on a moving paper to show how velocities add and subtract.

M-c1b

Linear Air Track: Position vs. Time

A glider travels down the 5 m air track while evenly spaced photogates record the elapsed time. One can then plot the position versus time for the glider on an overhead. The track may be inclined for uniformly accelerated motion.

M-c1c

Linear Air Track: Instantaneous Velocity

An air track glider passes through two pairs of closely spaced photogates with each pair separated by 2 meters, enabling instantaneous velocities, accelerations, and predicted distances to be calculated.

Uniform Acceleration

M-c2a

Dime and Feather Tube

A penny and a feather fall freely inside a glass cylinder that can be evacuated.

M-c2c

Basketball and Tennis Ball drop

Basket and Tennis balls are dropped simultaneously from the same height.

M-c2b

Inclined Air Track

Prop up one end on an air track and use photogates to time the glider's voyage.

M-c2d

Video: 405 the movie

2000 film of a plane making an emergency landing on top of Jeep: http://www.405themovie.com/. 3min13sec. (For amusement purposes)

Measuring g

M-c3a

Timed Free Fall -- Lecture Hall

A metal ball is dropped from 1m and then from 4m into a catch bucket; a precise digital timer records the time of flight for each fall. [May conflict with Shoot-the-Monkey or Timed Free Fall.]

M-c3b

Timed Free Fall -- Classroom

A metal ball is dropped from 0.5m and then from 2m; a precise digital timer records the time of flight for each fall.

M-c3c

Timed Free Fall -- Newton's g Ball

Newton's g-ball's built-in stopwatch measures free fall times for arbitrary throws

Motion in Two Dimensions

Displacement in Two Dimensions

M-d1a

Mounted Rotating 2D figure

An asymmetrical slab that can be mounted and rotated.

M-d1f

Balls on Rotating Disk

A disc with two balls mounted at different radii rotates at varying speeds. A third ball may be placed in the center if disk is horizontally mounted. Both orbital and spin rotations may be seen.

Velocity, Position, and Acceleration

M-d1e

High road low road - large version

Two balls race, one following a straight channel and the other along a channel with a valley.

M-d1g

Galileo's Circle - Inverted

Two balls following different chords of a circle hit base at the same time.

Motion of the Center of Mass

M-d4b

Throwing Foam Slab

A slab of foam has its center of mass marked with a black dot; this dot follows a parabolic path when the slab is thrown.

M-d4c

Pendulum Air Cart

This air track glider has a heavy pendulum; when the pendulum is set swinging the glider moves in the opposite sense. Collisions with the track bumper show interesting behavior

M-d4e

Air Track Inchworm

Two air track gliders coupled by a spring will oscillate about the center of mass that is marked by a flag.

Central Forces

M-d5d

Ball on a String

Attach a lightweight ball to a string and twirl

M-d5a

Orbit Ball

This consists of a large and a small ball attached to opposite ends of a string which passes through a metal handle. The light ball is twirled and the centripetal force is provided by the weight of the heavy ball.

M-d5b

Conical Pendulum

Three balls, suspended by differing lengths of string from the same height on a rotating shaft, rotate in the same horizontal plane.

M-d5c

Swing the Bucket

Swing a bucket of water in a vertical circle and then in a horizontal circle over your head.

M-d5e

Chain Wheel

A loop of chain is rotated very fast and then released onto the demo table, where it runs over obstacles while retaining its circular form.

Deformation by Central Forces

M-d5k

Rotating Tank

A large but thin, clear rectangular box is half-filled with colored water and rotated. The water surface forms a parabola.

Centrifugal Escape

M-d5m

Tangential Velocity

This demo uses an apparatus that rotates a ball on a string and that provides a means to cut the string while the ball is in flight.

M-d5n

Ball and Hoop

A hoop that confines a ball to a circular orbit is suddenly removed

M-d5p

Grinding Wheel

Sparks fly off the grinding wheel in a straight line.

M-d5o

Falling off the Merry-go-round

Blocks lined up radially on a turntable fall off in succession as the turntable speeds up.

Projectile Motion

M-d6c

Jumping Ball on Cart

A ball projected vertically upward from a wheeled cart falls back into the muzzle.

M-d6b

Jumping Block -- Air Track

A ball projected vertically upward from a moving air track glider falls back into the muzzle.

M-d6d

Balls Shot and Dropped -- Lecture Hall

A ball is dropped and simultaneously another is projected horizontally; they hit the floor at the same time. [May conflict with Shoot-the-Monkey and Timed Free Fall.]

M-d6f

Balls Shot and Dropped -- Classroom version

A ball is dropped and simultaneously another is projected horizontally; they hit the floor at the same time.

M-d6j

Blocks Nudged and Hit

A meter stick, fixed at one end, is bent and released to simultaneously knock blocks off the table.

M-d6e

Shoot the Monkey

An air-gun shoots at a monkey, released when the air-gun is fired; the bullet hits the monkey in mid-air. [May conflict with Timed Free Fall or Balls Shot and Dropped.]

M-d6i

Shoot the Monkey -- Classroom version

A shoot-the-monkey demo suitable for a normal size classroom

M-d6h

Mini Shoot the Monkey

A minified version of the shoot-the-monkey demonstration.

M-d6g

Range of a Gun

Shoot at 45, then calculate 30 or 60 and place the target

C-2

Comic: Projectile Problem with Pirate

Foxtrot Comic of doodling a pirate scenario on a projectile problem assignment

C-3

Comic: Snowball Throw Calculation

Foxtrot comic of getting smacked while mentally calculating snowball throw parameters

M-d6k

Parabolic Trajectory Mechanical Model

A wooden rod with equally-spaced pendula models a parabolic trajectory.

Relative Motion

Moving Reference Frames

M-e1a

Crossing the River

A battery powered tank runs at constant speed on a sheet of paper that is pulled in a direction perpendicular to the tank's velocity.

M-e1b

Movie--Frames of Reference

Classic Movie with 20 consecutive clips of relative motion puzzles with explanations. URL: https://www.youtube.com/watch?v=aRDOqiqBUQY

Coriolis Effect

M-e3a

Water Stream on Rotating Platform

Watch a horizontally-ejected stream of water falling into a pan, all mounted on a rotating platform, when the whole starts to rotate.

Newton's First Law

Measuring Inertia

M-f1a

Inertia vs Weight -- Balls

Push or hit a suspended bowling ball and a styrofoam ball.

Inertia of Rest

M-f2a

Inertia Masses

A 100 g mass is suspended from a 1 kg mass which is suspended from a crossbar. A sharp downward pull breaks the lower thread; a slow pull the upper thread.

M-f2d

Tablecloth Pull

Yank a tablecloth from under a bottle of wine, beer, and a book.

M-f2b

Hammered Blocks

The bottommost of a stack of blocks, when struck sharply, will slide to the side while the upper blocks remain in place.

M-f2e

Card and Ball Snap

Flick a card from underneath a ball and the ball falls into a cup.

M-f2c

Loose Hammer Head

The head of a hammer will remain in place when the handle is struck from above or below.

Inertia of Motion

M-f3a

Glider on Level Air Track

A glider on a level air track persists in gliding.

M-f3b

Block on a Cart

A block is placed on a rolling cart; when the cart is stopped, the block continues.

Newton's Second Law

Force, Mass, and Acceleration

M-g1d

Second Law--Fan Propelled Cart

Launch a fan-propelled (constant acceleration) cart down the track and observe what happens when its mass is varied.

M-g1a

Spring-Pulled Air Cart

An air track glider is pulled by a spring held at constant extension.

M-g1f

Heavy Cart pulled by Spring Scale

A cart loaded with masses is pulled by a spring held at constant extension.

M-g1b

Newton's Second Law on air track

An air track glider whose weight can be varied is attached to one end of a spring that has its other end fixed. The glider is pulled back and released; a photogate records its transit time at one point before the glider collides with the compressed spring.

M-g1g

Cart accelerated by hanging mass (with sensors)

A cart accelerated by a string attached to a hanging mass has its string mass tension, cart position, and cart velocity measured in real time. The mass of the cart and the string tension can be varied.

M-g1h

Cart with Force and Motion Sensors - Variation 2

Use rubber band to launch a cart with mounted force sensor along with a motion sensor to examine the force, position, and velocity during the launch and subsequent motion. The cart mass of the cart and the spring force can be varied.

M-g1e

Spring Scale vs Pan Balance

Show and tell a mass on a spring scale and a pair of masses on a pan balance.

M-g1c

Atwood's Machine

Two equal masses are hung from a pulley. A small amount of mass is transferred from one side to the other.

Accelerated Reference Frames

M-g2b

Elevators -- Spring and Mass

Quickly raise and lower a spring scale loaded with a mass NEW

M-g2a

The "Anti-Gravity" Plumb Bob

A balloon filled with helium is suspended from the bottom of a box and the box is pushed.

M-g2c

Jumping on the Trampoline

Jump on a trampoline with an accelerometer in your pocket

Newton's Third Law

Action and Reaction

M-h1f

Force Sensors on Colliding Cars

Measure the forces on each of two colliding cars, one heavy and one light, using force sensors.

M-h1c

3rd Law with Scales

Pull on two coupled spring scales with springs of equal or unequal strength.

M-h1e

3rd Law with Bathroom Scales

Have two students push against bathroom scales laid back-to-back to verify that each scale reads the same.

M-h1a

Push Me Pull Me Carts

Two people stand on roller carts and both pull on a rope or push with a long stick.

M-h1d

Fan Cart with Sail

A cart with a sail propelled by a battery powered fan shows interesting third law behavior.

M-h1g

Jumping off a Bathroom Scale

Jump off a force-sensor equipped bathroom scale.

M-h1i

Jumping off a Cardboard Box

A cardboard box that supports a human weight crumbles when the human jumps.

Recoil

M-h1b

Tennis Ball Cannon

A cannon mounted on an air track glider shoots out a tennis ball horizontallly.

Statics of Rigid Bodies

Finding Center of Gravity

M-j1a

Hanging Shapes

Suspend a 2-dimensional shape from holes drilled near the edges, and use a plumb bob to find the center of gravity.

M-j1d

Meter Stick on Fingers

Slide fingers together under a meter stick to come together at center of mass. Repeat with mass attached to one end of stick.

Exceeding Center of Gravity

M-j1b

Photo: Pisa's Leaning Tower

Digital image of the photo from Bloomberg's sixth floor of the Leaning Tower of Pisa. May be projected in the auditorium.

M-j1c

Center of Gravity Blocks

Stack blocks stairstep fashion at the edge of the table until the topmost block sticks out beyond the table edge.

Stable, Unstab., and Neut. Equil.

M-j2a

Stable and Unstable Equilibria

Two large rings each with two masses that have radially adjustable positions. Stable, unstable, and neutral equilibrium can be shown.

M-j2f

Weebles

This child's toy is weighted so that it rights itself from all but one position.

Stable and Unstable Equilibrium

M-j2b

Tight Rope Walker

The Tight Rope Walker consists of a pulley with four heavy lead weights on long semi-stiff wires symmetrically mounted around it. When placed on the "rope" (Cord), the weights hang down well under the rope, leaving the center of the Walker's mass below the rope and thus making it easy for the Walker to keep its balance.

M-j2c

Tilted Pop Can

A partially filled pop can when tilted appropriately will remain tilted

M-j2e

Balancing Bird

The balancing bird is an example of stable equilibrium.

M-j2d

Fork on Nail

Bend a fork so that it balances on the head of a nai

Resolution of Forces

M-j3a

Suspended 3-4-5 Block

A 1 kg mass rests on a 3-4-5 incline (e.g. incline angle = arctan(3/4)). Forces parallel and perpendicular to the incline will support the mass in mid-air when the incline is removed.

M-j3e

Tension in a String

The weight of a mass hung from a spring scale is compared to the weight shown on a spring scale between two masses over pulleys

M-j3d

Four scales in a row

A mass is hung at the end of a series of spring scales

M-j3f

Scale-Mass-Scale-Mass

A mass is hung at the end of a series of spring scales with an intervening mass.

M-j3c

Rope and three students

Two large strong students pull on the ends of a rope and a small student pushes down in the middle.

M-j3g

Rope, three students, pulley, and scale

A rope is pulled taut by two students; a third pulls up on the rope with a scale moving along the length of the rope

M-j3b

Force Board

This is a circular, ruled force table with four moveable pulleys arranged around the edge; four strings pull on a ring in the middle with masses hanging from each string. Used to show the vector sum of forces.

Static Torque

M-j4a

Torque Bar

A long thin rid mounted perpendicular to a bar handle holds a 2 kg mass on a sliding collar.

M-j4e

Movie: Milwaukee Pitstop Ad

A humorous, fake video showing a car being rotating by a torque wrench. https://www.youtube.com/watch?v=uzoFqumBCvY

M-j4d

Wrench, Nut, and Bolt

Use a wrench, nut, and bolt to illustrate torque.

M-j4b

Equal Arm Balance

Combinations of weights and distances on either side of the fulcrum of the equal arm balance may be selected to produce equilibrium. An oblique arm is used to show that the effective length of the lever arm is set by the component of the force.

M-j4c

Mass on Bar between Scales

A horizontal beam with a sliding 1 kg mass is hung between two spring scales.

M-j4f

Roberval Balance

A model of the Roberval platform balance.

M-j4g

Crane Boom

A model of a crane boom, with scales to show applied forces.

Applications of Newton's Laws

Dynamic Torque

M-k1a

Pushing the Refrigerator

Depending on where a large rectangular box is pushed, it will slid, tip, or turn.

M-k1b

Ladder against a Wall

Set a ladder against the wall and walk up the rungs until the ladder begins to slide.

M-k1c

Walking the Spool

The spool can roll forward or backwards when the string is pulled, depending on the angle of pull.

M-k1e

Walking the Spool variation 1

Arrange a weight and pulley to pull on the spool, and the spool will roll to equilibrium at the critical angle.

M-k1f

Pull the Bike Petal: Tricycle

Pulling on the petal at its lowest position causes the bike to move in the direction of the pull.

Applications of Newton's Law

M-k1d

Disk, Cart, Ruler slide

Push a ruler across the top of a large disk resting on the axles of a cart frame. Which way will the cart move?

Applications of Newton's Laws

Friction

M-k2a

Friction Cars on Inclined Plane

The static or dynamic forces required to move teflon-coated, rubber-coated, and wooden carts on an inclined plan are displayed on a spring scale

M-k2b

Rolling Friction -- Happy and Unhappy Balls

Race the happy and unhappy balls down an inclined plane

M-k2c

Measuring Friction on Flat Surface

The static or dynamic forces required to move teflon-coated, rubber-coated, and wooden carts are measured with the Vernier wireless force sensor

M-k2d

Operation of a Capstan

Demonstrate the frictional force of a capstan as the number of turns increases

Pressure

M-k3a

Bed of Nails

Lie down on a bed of nails.

Gravity

Univ. Gravitational Constant

M-L1a

Movie: Cavendish Balance

Time lapse of the Cavendish Experiment on Videodisk.

Orbits

M-L2a

Gravitational Well

A large fiberglass vortex-shaped cone is used to show circular and elliptical orbits and conservation of angular momentum.

M-L2g

Ball Orbiting inside Cone

A large glass cone is used to show circular and elliptical orbits, conservation of angular momentum, and the speed-height paradox.

M-L2c

Satellite Launch Applet

Animation launching a satellite tangentially to earth surface, as function of velocity: http://www.phy.ntnu.edu.tw/ntnujava/msg.php?id=47

M-L2e

Movie: Motion of Attracting Bodies

Meeks' animated 1976 film (6:53 min) on Newton's Laws and Earth's Gravity

M-L2b

Styrofoam cup -- conic sections

A cone is cut in circular, elliptical, parabolic, and hyperbolic cross sections.

M-L2d

Animation: Kepler's Laws Applet

Animation illustrating Kepler's first, second, and third laws: http://www.phy.ntnu.edu.tw/ntnujava/viewtopic.php?t=25

M-L2f

Movie: Planetary Motion and Kepler's Laws

Meek's 1974 animated film (9:22 min) on planetary orbits and Kepler's Laws

Work and Energy

Work

M-m1a

Pile Driver

Drive a nail into a block of wood with a pile driver.

Simple Machines

M-m2a

Simple Pulley

Show a simple pulley in equilibrium

M-m2b

Compound Pulley

Weights of a proportion of 5-to-1 are the equilibrium conditions for this compound pulley.

M-m2e

Double Pulley Setup

A 500g mass balances a 1000g mass in a two pulley system; can show that the work done by each in moving is the same.

M-m2d

Bosun's Chair -- Single Pulley

Subject in harness with attached rope that flows through overhead pulley, pulls self up with a force equal to half subject's weight.

Work-Energy Theorem

M-m2c

Spring Launched Cart on Level Track

A spring (of measurable spring constant) launches a cart (with measurable final veloctiy) on a level air track. Mass of cart can be varied.

Non-Conservative Forces

M-m3a

Decelerated Pendulum Rider

A pendulum hits a level board, transferring a mass rider that slides to a stop.

Conservation of Energy

M-m4a

Bowling Ball Pendulum--Energy Conservation

A bowling ball pendulum is pulled back until it touches the lecturer's nose and let go. The lecturer does not move.

M-m4b

Galileo's Pendulum and Nail

A pendulum started at the height of a reference line reaches the same height when its swing is intercepted by a post that effectively shortens the length of the pendulum.

M-m4n

Pendulum catch trick

A string with one hex nut at one end and 15 at the other is held by the single hex nut, with the rest of the string lying over a finger of the other hand. Release the nut. From Steve Spangler.

M-m4c

Loop the Loop

A rolling ball must be released from a height equal to 2.7 times the radius of the loop.

M-m4d

Ballistic Pendulum with Gun

A ball is shot out of a fixed, spring-powered gun into a pendulum which traps the ball.

M-m4e

Spring Launched Air Cart

Predict the height to which a spring-compressed glider will rise on an inclined air track given the mass, spring constant, and amount of spring compression. Do the experiment.

M-m4f

Spring-Launched Rolling Cart

Predict the height to which a spring-compressed cart will rise on an inclined plane given the mass, spring constant, and amount of spring compression. Do the experiment.

M-m4h

Ping-Pong Slingshot

Shoot Ping Pong Balls at unbelievers in energy conservation.

M-m4k

Toys - Jumping

A spring-loaded object (jumping disk; jumping frog) can often jump many times its own height.

M-m4m

Rollback Can

A rubber band with attached mass winds up when the can is rolled, causing the can to roll back as the rubber band unwinds.

M-m4g

Rattleback

The rattleback, or celt, will slow down and reverse direction when rotated against its preferred rotational direction.

M-m4j

Hopper Popper

The hopper popper will store and release energy.

M-m4i

Movie: Honda Cog

Two-minute Honda movie ad of a series of mechanical cogs bumping into each other in sequence. http://www.youtube.com/watch?v=EEF0cg1j35

M-m4l

Movie: OK Go - This Too Shall Pass (Rube Goldberg Machine)

Rube Goldberg type sequence of collisions set to "This too Shall Pass" at http://www.youtube.com/watch?v=qybUFnY7Y8w

Linear Momentum and Collisions

Impulse and Thrust

M-n1c

Measuring Impulse with Force Sensor

A force sensor mounted on a cart collides with a barrier, and different force vs. time curves are obtained when the cart bumper is changed.

M-n1a

Lacrosse Ball Compression/Impression

Drop a lacrosse ball on down-ward facing carbon paper, and then press down on the ball until it is squashed the same amount.

M-n1b

Egg in sheet

Throw an egg into a sheet held by two people.

Conservation of Linear Momentum

M-n2d

Spring apart air track gliders

Cut a string between two air track gliders compressed by a spring. Either 150g carts, 300g carts, or one of each can be used.

M-n2c

Spring apart Pasco carts

Tripping the spring between two Pasco carts launches them in opposite directions; the cart masses may be varied.

M-n2f

Spring apart Vernier carts with Magnets

Hold the two carts gether, and then release them; the cart masses may be varied.

Rockets

M-n2a

Fire extinguisher wagon

Mount a fire extinguisher on a cart and take a ride.

M-n2j

Alcohol Vapor Rocket

The combustion of alcohol vapor propels a 5 gallon whoosh bottle across the stage.

M-n2b

Water Rocket

A toy rocket is launched twice, once when pumped up with air and once when pumped up with water.

M-n2g

Rocket Car -- Vinegar and Baking Soda

Vinegar and Baking Soda combine to blow out the stopper and propel this rocket car. Vinegar & Soda not shown.

M-n2h

Two Litre Bottle Rocket -- Air Pressure

Use a bicycle pump to pressurize a 2L bottle; pull the catch to release.

M-n2i

Foot Long Rocket -- Air Pressure

Use a bicycle pump to pressurize this rocket; pull the catch to release.

M-n2k

Ball Bearing Rocket Car

A Cart accelerates as each ball rolls off.

M-n2e

Sparkler Sprinkler

A sprinkler-shaped configuration of two sparklers rotates with lit.

Collisions in One Dimension

M-n3a

Newton's Cradle

Five adjacent metal balls on a bifilar suspension illustrate momentum conservation properties.

M-n3c

Elastic Collisions on Air Track

Elastic collisions between air track gliders of equal and/or unequal mass.

M-n3d

Inelastic Collisions on Air Track

Inelastic collisions between air track gliders of equal and/or unequal mass.

M-n3g

Happy and Unhappy Ball Collisions

A happy ball rolls down the incline and knocks the block over; the unhappy ball does not.

M-n3e

Supernova

A tennis ball is placed on top of a basketball and both are released from rest.

M-n3f

Astroblaster

Four balls of progressively smaller diameter resting on top of one another are dropped to the floor.

Collisions in Two Dimensions

M-n4a

Air Table

Can use to illustrate the properties of momentum in two dimensions with these pucks that glide freely over an air table.

Rotational Dynamics

Moment of Inertia

M-q1a

Inertia Wands

Students twirl equal mass wands, one with the mass concentrated in the middle, the other with the mass concentrated at the ends.

M-q1b

Ring versus Disk Race

The Matched Disk and Ring are identical in diameter and mass. When rolled down the inclined plane, the disk wins the race due to its lower moment of inertia.

M-q1c

Racing Disks

Two disks of identical mass, one weighted in the center and the othe weighted at the rum, are rolled down an incline.

M-q1d

Racing cylinders

3 Cylinders of identical mass and appearance accelerate down an incline at different rates.

M-q1e

Racing cylinders -- different mass

Yet another set of disks to race, including cylinder pair of uniform density but different mass.

M-q1g

Video - Tire Ski Jumping

Video of a Japanese test of the jumping and rolling performance of six different tires.

Rotational Energy

M-q2a

Whirlybird

Two equal masses with adjustable positions are mounted on a radial bar fixed to a horizontal axis with a pulley. A weight on a string rotates the assembly.

M-q2d

Instrumented adjustable whirlybird

Two equal masses with adjustable positions are mounted on a radial bar fixed to a verticle axis with a pulley. A weight on a string traveling over a Vernier smart pulley enables the radial position and velocity to be measured.

M-q2b

Massive Atwood's Machine

Atwood's machine with a large, massive pulley.

M-q2c

Toppling Chimney

A column of two sticks, one on top of the other, is pushed until it topples

Transfer of Angular Momentum

M-q3a

Disc Dropped on Rotating Disk

Drop a stationary disk on top of a rotating disc.

Conservation of Angular Momentum

M-q4a

Rotating Platform and Weights

Spin on a rotating platform with a dumbbell in each hand.

M-q4b

Swinging Bat on Rotating Platform

Stand on a rotating platform initially at rest, and swing a bat or a mallet.

M-q4f

Collapsing Star

Collapse a spinning suspended Hoberman Sphere into a small ball.

M-q4c

Bike wheel on rotating platform

Invert a spinning bicycle wheel while standing on a rotating platform.

M-q4d

Rotating Platform and Mallet

Rotate yourself one full revolution using a mallet.

M-q4g

Train on Circular Track

A train rides on a circular track mounted to a rotating platform.

M-q4e

Angular Momentum Funnel

The angular speed of a ball bearing increases as it approaches the bottom of a large glass funnel.

M-q4i

Angular Momentum Vortx

The angular speed of a quarter or steel ball increases as it rotates through ever-smaller circles down the Vortx.

M-q4h

Balloon Helicopter

A balloon is attached to a Hero's engine-type arrangement of wings

Gyros

M-q5f

Throwing Top

A classic throwing top

M-q5a

Precessing Disk

Spin a metal disk on a nail inserted in a central hole and touch a finger to the rim. [Broken]

M-q5b

Toy Gyroscope

The toy gyroscope has a knob on the end of an axis that fits into a hollow in a separate mound. Useful demo for a small classroom.

M-q5c

Bicycle Wheel Gyro

The bike wheel is hung from its axle by a wire attached to the ceiling; when spun the bike wheel illustrates gyroscope motion nicely.

M-q5g

Double Bike Wheel Gyro

Two bike wheels are mounted coaxially; when wheels spin in opposite directions the gyroscopic effect disappears.

M-q5d

MITAC Gyroscope

This motorized gyroscope, used in the teaching labs, is good for showing a gyroscope's directional constancy; precession due to applied torques, and nutation.

M-q5e

Gimbaled Gyroscope

An old aircraft navigational gyroscope that spins fast and shows the gyroscope's ability to maintain its orientation in space

Rotational Stability

M-q6d

Perpetual Top

This top will keep spinning until the battery runs out.

M-q6b

X-zyLo the Flying Gryo

A slender collar is spun as it is launched

M-q6a

Good, Bad, and Giant YoYos

Comparison between well and poorly designed yoyos

M-q6f

Euler's Disk

Euler's disk dissipates a minimum of energy and momentum as it spins; the spin ends in a finite-time singularity.

M-q6c

Tippe Top

The tippe top flips when it spins.

M-q6e

Whirling Spiral Toy

This toy whirls with more stability when its arms are spread out compared to when the arms are aligned. Esoteric

Properties of Matter

Hooke's Law

M-r1a

Stretching a Spring: Hooke's Law

Add masses to a spring and measure displacement.

M-r1b

Stretching a Horizontal Spring: Hooke's Law

Use a spring scale to pull on a mass attached to an airtrack by a spring.

Tensile and Compressive Stress

M-r2a

Breaking Wire

Suspend a wire from the ceiling and add masses until the wire breaks.

M-r2b

Young's Modulus

Hand weights from a wire, and use a laser and mirror-mounted-on-lever to display the elongation.

M-r2c

Poisson's Ratio with rubber tube

The striped tube can be stretched to show lateral contraction with increasing length.

M-r2d

Bend the Wall

Push on a concrete wall and the wall's deflection is detected by the deflection of a laser beam

M-r2e

Bend the Table

Stand on the demo table and show the tabletop deflection by the dispalcement of a laser beam.

Shear Stress

M-r3a

Deformation of Thick Book

The large book can be pushed perpendicular to the spine to show shear.

M-r3b

Striped Tube Twist

The striped tube can be twisted to show torsion.

Coefficient of Restitution

M-r4b

Atomic Trampoline

Compare a steel ball bouncing on an amorphous metal to one bouncing on stainless steel.

M-r4a

Happy and Unhappy Balls

Two black rubber balls of about 1.5 cm diameter are dropped from a height simultaneously. One ball bounces high while the other barely rebounds. Great to pass around.

Crystal Structure

M-r5a

NaCl crystal model

NaCl model made of wooden balls connected by metal sticks.

M-r5b

Ball and Spring crystal model

Cubic crystal model made of plastic balls connected by springs.

M-r5c

BB Board -- Crystal Faults Model

A layer of spheres sandwiched between clear acrylic panels illustrates slip planes, grain boundaries, and vacancies.

Fluid Mechanics

Surface Tension

Force of Surface Tension

F-a1a

Floating Metals

Float a razor blade, a paperclip, and a needle on the surface of water.

Minimal Surface

F-a1b

Ring and Thread

A loop of thread inside a soap film forms a circle when the film interior to the loop is popped.

Capillary Action

F-a2a

Capillary Tube

Compare the height of water in different diameter tubes

Statics of Fluids

Static Pressure

F-b2a

Pascal's Vases

Tubes of different geometries rise vertically out of a common reservoir of colored water.

F-b2f

Hydraulic Press

Break a piece of wood in a hydraulic press.

F-b2b

2L Bottle Hydraulic Press

Push up a quarter (mass ~2 grams) with a 0.5cm diameter tube, then attach to the cutoff 2L bottle (dia. ~ 10 cm) and lift up a soda bottle (~ 800 grams)

Atmospheric Pressure

F-b3c

Crush the Can--water condensation

Heat water in a can until boiling, then cap and remove from heat.

F-b3d

Indent the Can--cooling of air

Heat the air inside the can until it's hot, cap, and remove from heat.

F-b3a

Crush the Can--with pump

A vacuum pump evacuates a 1 gallon can; atmospheric pressure crushs the can.

F-b3j

Vacuum Pack a Student

A plastic bag covering a student up to the neck is evacuated with a vacuum cleaner.

F-b3b

Magdeburg Disks

Evacuate Magdeburg hemispheres and try to separate them.

F-b3f

Magdeburg Disks -- Hanging from Ceiling

The space between two plates is evacuated; one plate hangs from the ceiling and a person sits on a seat attached to the other.

F-b3h

Suction Cups

Press together two suction cups and try to pull them apart.

F-b3k

Inverted Glass surprise

Fill a glass part way with water, cover with a stiff card, and invert.

F-b3i

Egg in a Bottle

Put a lighted match inside a milk bottle and cover with a peeled hard-boiled egg.

F-b3g

Lift with Rubber Sheet

A stool is lifted by means of a rubber sheet with a handle lain on top.

F-b3e

Vacuum Ping Pong Ball Cannon

Atmospheric pressure shoots a ping pong ball through an aluminum can.

Density and Buoyancy

F-b4a

Weigh Submerged Block

A 2 kg Al cylinder, suspended from the 20 N spring scale, is lowered into water and the new weight is observed; Can have beaker on scale; Can lower into oil for comparison

F-b4g

Finger in Water

Ask what will happen when a finger is inserted into a beaker of water balanced on a pan balance.

F-b4h

Sulfurhexafluoride Boat

An aluminum boat floats on a sea of Sulfur Hexafluoride gas

F-b4f

Ice Melting in Water

Show that the water level doesn't change when the ice in a beaker of ice water melts.

F-b4b

Cartesian Diver - Squidy

Squeeze the bottle to sink the diver.

F-b4d

Coke and Diet Coke

An unopened diet soda can floats in water, and a regular soda can sinks.

F-b4i

Sulfurhexafluoride Balloon

A SF6-filled balloon falls to the floor with a thud.

F-b4c

water and oil "U" tube

Water and oil rise to different heights in a "u" tube.

F-b4e

Floating Balloons

Helium filled ballons trailing masses float without rising or sinking.

F-b4k

Hot Air Balloon

Use a hair dryer to launch this hot air balloon.

F-b4m

Solar Bag

Blow up this bag, tie it down with string, place it out in the sun, and watch it rise.

F-b4j

Asphyxiation of flame by CO2

Pour gaseous carbon dioxide over a flame to extinguish it

F-b4n

Flame climbing ether in trough

Vapor from an ether-soak rag drifts down a trough at the bottom of which is a candle flame.

Siphons, Fountains, Pumps

F-b6a

Cup of Pythagoras

A clay drinking vessel designed to empty itself when filled beyond a certain level.

Dynamics of Fluids

Flow Rate

F-c1a

Torricelli's Tank

Water streams out from three holes at different heights in a tall cylinder.

Forces in Moving Fluids

F-c2a

Venturi Flowmeter

Air flows through a restricted glass tube to the atmosphere; the pressure at different points of the tube is shown by manometers.

F-c2d

Windbag

Blow up an 8-foot long bag with one breath.

F-c2b

Floating Ping Pong Ball

A ping pong ball floats in an upward stream of air.

F-c2h

Floating Beach Ball

A beach ball ball floats in an upward stream of air.

F-c2i

Toilet Paper Cannon

Send streamers of toilet paper some dozens of feet into the air.

F-c2c

Funnel and Ball

A ping-pong ball is supported by air streaming out of an upside down funnel.

F-c2k

Fan blowing on Board

A fan blows on a board mounted so that it can rotate about an axis in the wind. What orientation will the board take?

F-c2L

Falling Card

Hold one of these cards horizontally in the air, and then drop one to observe the dominate behavior of the card orienting itself horizontally, as well as the slipping and rotating behavior believed due to turbulence.

F-c2g

Bernoulli Paper Lift

Raise a strip of paper by blowing just above its surface

F-c2j

Lifting Plate - Spool and Card

Stick a pin in a card, insert into a spool, and blow through the other end to lift the card.

F-c2f

Curving Baseball

A relatively complicated apparatus that holds and spins a ping pong ball and has an attachment to hit the ball, resulting in a curved trajectory.

F-c2m

Launch of rotating cylinder

Wind a rubber strip around a cylinder, pull, and launch into an aerodynamically influenced trajectory.

F-c2e

Ping Pong Ball and Racket

Use a ping pong racket to hit a curve ball using a 2-3" diameter styrofoam ball or a ping pong ball.

F-c2n

Spitball in Bottle Mouth

Place a crumbled paper ball in the mouth of a two litre bottle and attempt to blow the ball into the bottle with a straw.

Viscosity

F-c3a

Ball Drop in Oil

A steel ball is dropped into a tall cylinder filled with water and then with corn syrup.

F-c3b

terminal velocity--coffee filters

Drop a coffee filter and it descends at a low terminal velocity. Crumble it and it free falls.

F-c3c

Coffee Filter Drop

One coffee filter dropped from one meter and four coffee filters dropped from 2 meters hit the ground at the same time, demonstrating that the drag force is proportional to the square of the velocity

Turbulent and Streamline Flow

F-c4d

Swimming in Corn Syrup Movies

Three movies showing a flap-drive in water, flap-drive in corn syrup, and corkscrew-drive in corn syrup, from Youtube.

F-c4b

Laminar Flow in Microfluidics Card

Observe water flow laminarly in a microfluidic circuit.

F-c4c

Movies: Laminar Flow in Pipe

Movies of laminar and turbulant flow in pipe from Youtube.

F-c4a

Couette Flow

Observe a drop of dye suspended in corn syrup or glycerin spread out as the outer cylinder is rotated with respect to the concentric inner cylinder, and return to a drop when the rotation is reversed.

Vorticies

F-c5a

Vortex Cannon

Pull and release the plastic diaphragm to blow vortexes; add smoke to blow smoke rings.

Non Newtonian Fluids

F-c6b

Fluidization of Sand

A column of sand behaves like a fluid when air flows through the column under pressure

F-c6a

Corn Starch in Water -- Oobleck

Add water to cornstarch to make a gooey, non-Newtonian fluid

Oscillations and Waves

Oscillations

Pendula

W-a1a

Simple Pendulum

A bob on a string hanging from a stand exhibits simple harmonic motion for small angles.

W-a1g

Force Sensor as Pendulum Bob

The Vernier WDSS as a pendulum bob shows the force on the bob as a function of altitude.

W-a1h

Human Pendulum--Mass of Bob

First swing the bowling ball pendulum, then replace the bowling ball with the lecturer to demonstrate the dependence of the period on the mass of the bob.

W-a1b

4-to-1 Pendula

One pendulum four times longer than a second oscillates with twice the period of the second.

W-a1c

Different mass pendula

Three pendula of different masses but the same length all oscillate with the same period.

W-a1f

Inverted Pendulum

A piece of spring steel mounted vertically from a heavy base with a mass on the end behaves like a two level system.

W-a1d

Torsion Pendulum

A steel cylinder is suspended by a steel music wire along its right axis. When the cylinder is displaced by rotation and released it will oscillate in simple harmonic motion.

W-a1e

Pendula Amplitude Dependence

Two identical simple pendula set in motion with different initial amplitudes, oscillate nonisochronically.

Physical Pendula

W-a1p

Physical Pendulum--Crossed Dumbbells

A physical pendulum of cross dumbbells with adjustable positions can be used to show the inertia effects and center of gravity effects.

Springs and Oscillators

W-a2a

Spring and Weight

A mass hangs on the end of a spring. Using two springs of different k and a variety of masses, show the effect of varying k and m.

W-a2f

Oscillating Human

The lecturer oscillates on a spring suspended from the catwalk

W-a2d

Springs in Series and Parallel

A spring with mass m, two identical springs in parallel with mass 2m, and two identical springs in series with mass m/2 oscillate with the same period.

W-a2g

Series and Parallel Springs with Human

Analog to Springs in Series and Parallel, but using a human as the bob and stronger springs.

W-a2c

Air track glider and Spring

Two identical air track carts are attached to (opposite) ends of an air track by means of two different springs. A mass may be added to either cart, and the dependence of the oscillation frequency on mass and on spring constant may be explored.

W-a2e

Glider and Spring with Motion Detector

A motion detector enables the time dependence of a glider's position, velocity, and acceleration to be displayed.

W-a2b

Spring and Air Cart

An air track glider is attached to a horizontal spring and displaced from equilibrium.

Simple Harmonic Motion

W-a4a

Projected SHM

Shadow project a ball mounted on a rotating disk.

W-a4b

Projected SHM Applet

Java Applet relating circular motion to a mass on a spring: http://www.phy.ntnu.edu.tw/ntnujava/viewtopic.php?t=13

Driven Mechanical Resonance

W-a6a

Tacoma Narrows Film

A 3 minute video of the collapse of the Tacoma Narrows Bridge. Very impressive and memorable.

W-a6d

Film: Puzzle of the Tacoma Narrows Bridge Collapse

The expanded 8.21 minute, 1979 version of the Tacoma Narrows Bridge Collapse, with additional context and detail.

W-a6b

Driven Cart Between Springs

An air track glider attached by springs to a mechanical oscillator, is swept through resonance.

W-a6c

Damped Driven Hanging Mass

A mass, supported by a spring whose support is driven, vibrates against a solid screen; the drive amplitude, frequency and the screen angle can be varied.

W-a6f

Damped Driven Hanging Mass--Showing Beats

The beats between the natural oscillation frequency and the driving frequency of a damped driven hanging mass are illustrated by using a force sensor between the driving system and the hanging mass.

W-a6e

Vibrations of Metal Strips

A mechanical vibrator drives a metal comb with different length tines through resonances.

Coupled Oscillations

W-a7a

Wilberforce Pendulum

Illustrates the transfer of energy between torsional and vertical oscillation modes.

W-a7b

Coupled Pendula

Two pendula are coupled with a light spring.

Normal Modes

W-a7c

Two Coupled Air Track Gliders

Two air track gliders are coupled with three identical springs.

W-a7d

Five Coupled Driven Air Track Gliders

Up to five air track gliders are coupled by identical springs driven at the normal mode frequencies.

W-a7e

Vibrating String with evenly spaced masses

Show normal vibrational modes of a "massless" string with up to six equally spaced masses.

Lissajous Figures

W-a8a

Lissajous Figures - Fourier Synthesizer and Scope

Harmonics of the Fourier Synthesizer's 440Hz fundamental are fed into the X and Y channels of an oscilloscope.

W-a8b

Lissajous Figures - Dual Function Generator

The outputs of the dual function generator are fed into the X and Y channels of an oscilloscope.

Non-Linear Systems

W-a9k

Amplitude Jumps

An air cart is driven between two springs. A magnet on top interacts with other magnets to perturb the potential and produce the jump effect.

W-a9m

Chaotic/Anharmonic Pendulum

A physical pendulum made of a ruler blade oscillates between between two disk magnets. This is a modification of a pendulum in the advanced lab.

W-a9n

Two Uncoupled, Physical Double Pendula

Two uncoupled, physical double pendula, each having one bob hanging from an upper bob, are used do demonstrate chaos.

W-a9o

Gee Haw Whammy Diddle

Rub a dowel along a ribbed stick with an attached propeller makes the propeller go round.

Wave Motion

Transverse Pulses and Waves

W-b1a

Pulse on 1.9m spring

Give the 1.9 m spring a quick pulse. The length and/or tension in the spring can be varied. Good for showing pulses, standing waves, harmonics, energy transfer.

W-b1b

Pulses on Torsional Wave Apparatus

Excite the short-bar and long-bar torsional wave machines by hand to show how the wave speed varies as the inertia of the medium (the rod length) varies.

W-b1c

Simple Reflections--Torsional Wave Apparatus

Send pulses down a torsional wave model machine with the other end free, fixed, or attached to a dash pot.

W-b1d

Pendulum Waves - Overhead Projector Version

A set of eight uncoupled pendula of monotonically increasing length that exhibit traveling waves, standing waves, and interesting patterns.

Longitudinal Pulses and Waves

W-b2a

Hanging Slinky

A long slinky is supported on a bifilar suspension, and the ends are taped to the lab stands, for showing longitutinal wave properties with minimal friction. [BROKEN]

W-b2b

Slinky

Two students stretch a slinky and send longitudinal waves down the slinky.

Standing Waves

W-b2e

Driven Rope Waves

A horizontal rope with a mechanical vibrator at one end and a weight over a pulley at the other end is used to show standing waves at different driving frequencies. [Needs Fixing]

W-b2f

Standing Waves on a String

Use a mechanical vibrator to generate standing waves on a string with one end under tension from a hanging mass. Best under UV light

W-b2g

Standing Waves on torsional wave machine

Excite standing waves on the torsional wave machine by hand

W-b2h

Simulation: Standing Waves on torsional wave machine

Simulation illustrating forbidden bands and standing waves specific to the torsional wave machine. http://www.pha.jhu.edu/~javalab/wavemachine.html

W-b2i

Standing Waves in Air - Schlieren View

Observe the formation of 28kHz standing waves in the cavity between a speaker and reflector. Small balls may also be levitated.

Inpedance and Dispersion

W-b2L

Coupling with Impedance Matching - Shive Machine

Waves emanating from the short-rod torsional machine are transmitted with minimal reflection to the long-rod machine when a third section of gradually tapering rods is inserted between them.

W-b2n

Reflection and Transmission at media boundaries--Shive Machine

See the incident, reflected, and transmitted waves at the interface of the short- and long-rod sections of the torsional wave machine.

W-b2k

Joined spring and cord

The 1.9 m spring is attached to a rubber cord; pulses started at one end will produce both transmitted and reflected pulses.

W-b2m

Pulse over trough edge

A slinky lies in a tilted channel raised above the table; pulling one point of the slinky onto the table causes a pulse to propagate along the channel, in mechanical analog to nerve conduction along axons.

Compound Waves

W-b2r

Wave Superposition -- Torsional Wave Apparatus

Send pulses simultaneously from both ends of one section of the torsional wave machine.

W-b2p

Wave Superposition--Long Spring

Send pulses simultaneously down both ends of the 1.9 m spring to show the addition of amplitudes.

W-b2q

Wave Superposition -- on scope

Electronically add two 440 Hz sine waves of different phases together on the scope and audibly.

Wave Properties of Sound

W-b3d

Speed of Sound by Phase Difference

A function generator drives a speaker, and an oscilloscope displays the signals from the function generator and a microphone that moves radially from the speaker.

W-b3a

Bell in a Vacuum

An alarm buzzer is suspended inside an evaculated bell jar, turned on, and the bell jar is evaculated. When air is let back into the jar, the sound returns.

W-b3c

Speaker and Candle

A large speaker operating at low frequency and large amplitude makes a candle flame oscillate.

W-b3b

Helium voice (or recorder)

Fill your lungs with helium and then talk, sing, or blow a musical instrument.

W-b3g

SF6 voice (or recorder)

Fill your lungs with sulfer hexafluoride and then talk, sing, or blow a musical instrument.

Phase and Group Velocity

W-b3f

Wave and Group Velocity on Scope

Display the signals from two oscillations and their sum on the oscilloscope

W-b3e

Two Combs

Slide two combs across each other on the overhead projector

Doppler Effect

W-b4a

Doppler Buzzer

Swing a small battery powered buzzer on the end of a string in a circle over your head.

W-b4b

Doppler in Ripple Tank

Move the wave generator back and forth in the ripple tank.

W-b4d

Movie--The Doppler Effect in Sound and Light

Computer-animated film by Meeks, 5 min 50 sec in duration, on DVD.

W-b4c

Doppler with Stroked Aluminum Rod

Shake the stroked aluminum rod at the audience

Shock Waves

W-b4e

Photo of jet with vapor cone

Photograph of Airplane creating vapor cone shock wave

Interference and Diffraction

W-b5a

Single Slit in Ripple Tank

Diffraction from a plane wave passing through a single slit on the ripple tank mounted on the overhead projector.

W-b5c

Two Points in Ripple Tank

Two point source generators of ripples show interference patterns in the ripple tank on the overhead projector.

W-b5d

Double Slits in Ripple Tank

A plane wave impinges on a barrier with two slits in the ripple tank on the overhead projector.

W-b5b

Moire Pattern Transparancies

Transparancies with identical concentric circular patterns are placed on top of each other with a slight offset.

Interference and Diffraction of Sound

W-b5e

Two-Speaker Bar

A 2 meter long bar with a speaker at each end produces auditory interference patterns.

W-b5g

Two Speakers and Microphone

A moveable, free-standing microphone attached to an oscilloscope picks up the interference pattern produced by two identically-driven speakers.

W-b5f

Baffle and Speaker

Listen to a single bare speaker, then surround it by a baffle.

Beats

W-b6a

Beats with Tuning Forks

Two tuning forks of identical frequency are mounted on resonant enclosures; when a small piece of wax is attached to one, beats can be heard.

W-b6c

Beats with Tuning Forks and Oscilloscope

Examine with an oscilloscope the beats from two identical tuning forks mounted on resonant enclosures.

W-b6b

Beats on Scope

Two audio signals are fed through a summing amplifier and the result is presented on the oscilloscope and a speaker.

W-b6d

Beats on Scope with Fourier Synthesizer

Use two higher overtone frequencies of the Pasco Fourier synthesizer to produce and hear beats.

Coupled Resonances

W-b7a

Coupled Tuning Forks

Strike one of two matched tuning forks mounted on resonant boxes and the other vibrates too.

Acoustics

Pitch

W-c1a

Range of Hearing

Use a function generator and wide-range speaker to demonstrate the range of hearing.

Wave Analysis and Synthesis

W-c5a

Pasco Fourier Synthesizer

Construct, hear, and see waveforms built from the 440 Hz fundamental and up to eight harmonics.

W-c5d

Java Fourier Synthesizer NTNU

Construct, hear, and see waveforms built from up to fifteen harmonics: http://www.phy.ntnu.edu.tw/java/sound/sound.html

W-c5e

Java Fourier Synthesizer Falstad

Construct, hear, and see waveforms built from up to over a hundred harmonics: http://www.falstad.com/fourier/j2

W-c5f

Java Fourier Synthesizer Thole-Huber

Construct any waveform by specifying numerically up to 13 fourier components or inputing the analytical expression, and hear and see the resulting waveforms. built from up to over a hundred harmonics: http://homepages.gac.edu/~huber/fourier/

W-c5b

Fourier Analyzer - Oscilloscope

Use the FFT module of the Tektronix TDS3014 oscilloscope to examine the waveform and spectrum of sound waves.

W-c5h

Fourier Analyzer - LabPro

Use the LabPro with Logger Pro software to acquire and display the waveform and FFT from various sound-making instruments

W-c5c

Resolution of Fourier Analyzer - Oscilloscope

The width of the Fourier transforms depends on the length of the wave being analyzed and limits the resolution of the spectrum.

W-c5g

FFT Properties- LabPro and Falstad Synthesizer

Demonstrate data & FFT transform decreteness, (data length)(width of FFT peak) uncertainty, and aliasing using the LabPro FFT program and Falstad function generator or musical instrument

W-c5i

FFT of Boxcar Pulse

Use the Tektronix FFT function and a pulse generator to show the Fourier Transform of a square wave pulse.

Instruments

Resonance in Strings

W-d2a

Guitar

Hanging weights on the end of a "guitar" can be varied to "tune" the guitar to a desired pitch.

Resonant Cavities

W-d3a

Resonant Tube

A function generator driving a speaker generates standing waves in a long hollow tube; the end can be open or closed and the tube probed by a tiny microphone.

W-d3d

Bloogle

Whirl a corrugated plastic tube to produce sound. At least five tones can be heard.

W-d3g

Ruben's Tube

Show nodes and antinodes with the flames coming from a row of holes in a hollow tube filled with propane.

W-d3f

Kundt's Tube

Sawdust in a tube piles up at standing-wave nodes when driven by rubbing a rod attached to a disc.

Air Column Instruments

W-d3b

Organ Pipe

A closed-end, square wood organ pipe of adjustable length.

W-d3e

Conical Organ Pipes

A collection of conical pipes.

W-d3c

Trombone

A student-class trombone illustrates the effect of pipe length on resonant frequencies.

W-d3h

Palm Pipes

This set of PVC tubes can be used by a group to play America, Twinkle twinkle little star, Happy Birthday, and other songs.

Resonance in Plates, Bars, Solids

W-d4d

Stroked Aluminum Rod

An aluminum rod sings when stroked with rosin-covered fingers.

W-d4c

Chladni Plates

A driven Chladni plate covered with sand shows standing wave patterns. Noisy!

W-d4g

Musical Goblet

Rub the edge of a goblet with a wet finger to make it sing. An oscilloscope can be used to measure the frequencies.

W-d4h

Spouting Bowl

Generate sprays of water by rubbing the handles of this bronze vessel half-filled with water.

W-d4i

Styrofoam Cup Standing Waves

Generate sprays of coffee by sliding a filled styrofoam coffee cup across a table.

W-d4f

Shattering Wineglass with Sound

Shatter a wine glass with sound waves at the glass resonant frequency

Tuning Fork

W-d4e

Tuning Fork and Strobe

The motions of a 100 Hz and 440 Hz tuning fork can be heard and clearly seen with a strobe.

Thermodynamics

Thermal Properties of Matter

Solid Expansion

H-a3a

Bimetallic Strip

Strips of dissimilar metals bonded together bend when heated. Makes a nice thermometer.

H-a3b

Ball and Ring

The Ball will pass through the hole in the brass plate (termed the ring) when both are at room temperature. When the ball is heated with the torch it expands and will not pass through the ring.

Heat and the First Law

Heat Capacity and Specific Heat

H-b1a

Calorimeter and Steel Mass

The heat capacity of a 1 kg steel mass is measured by calorimetry.

H-b1b

Metals Sinking into Wax

Hot copper, lead, and aluminum cylinders at a common temperature are placed on a wax block.

Convection

H-b2a

Convection Tube

One side of a glass tube loop is heated while a drop of ink is inserted in the other side.

Conduction

H-b3a

Melting Wax on Rods

Three metal rods (Cu, Al, Steel), with wax mounted on the ends of each, radiate horizontally from a central heated disk. This is a race to see which melts first.

H-b3b

Ice Melting Blocks

A chunks of ice placed on an aluminum block melts much quicker than ice on a foam block.

Radiation

H-b4b

Light the Match

A match at the focus of one parabolic mirrir is lit by a heating element at the focus of another parabolic mirror.

H-b4c

Infrared Camera -- Blackbody Radiation

An infrared camera is aimed at the class and at various hot and cold heat sources.

H-b4a

Black and White Radiation

A thermopile with indicator is held to both sides of a hot coffeepot with one side painted black and the other side white.

Mechanical Equivalent of Heat

H-b6a

Dropping Lead Shot

One kg of lead in a 1 m long tube is inverted repeatedly and the temperature rise is measured.

H-b6c

Happy and Unhappy Balls in Infrared

An infrared camera shows the temperature rise in the unhappy ball as it is repeatedly hit with a wood block; the effect is much weaker in the happy ball.

H-b6b

Stretching Rubber Band

Stretch a rubber band or balloon and feel the heat generated with your lips.

H-b6d

Friction Tracks

An infrared camera shows the temperature rise due to the frictional forces acting on the floor as a foot or block is dragged across the floor.

Adiabatic Processes

H-b7a

Fire Syringe

A small (2mm x 2mm) piece of tissue is put at the bottom of the "fire torch," a clear glass cylinder that is closed at one end. When a plunger is inserted into the open end and rapidly pressed inwards, the tissue bursts into flames.

H-b7b

Quickly Plunging Plastic Piston

A thermocouple embedded in a cylinder-and-piston assembly causes a galvanometer deflection when the cylinder is pressurized.

Change of State

PVT Surfaces

H-c1a

PVT Surfaces

Three dimensional models, about 25 cm on a side, of the PVT surfaces for water and carbon dioxide.

Phase Changes: Liquid-Solid

H-c2a

Ice Bomb in Liquid Nitrogen

An iron vessel filled with water breaks when immersed in liquid nitrogen.

Phase Changes: Liquid-Gas

H-c3a

Boiling by Cooling

Use ice to cool a stoppered flask of hot water until boiling starts.

Cooling by Evaporation

H-c3b

Cryophorus

When one end of a glass tube with bulbs at each end containing water is placed in liquid nitrogen, the water at the other end starts to freeze. BROKEN

H-c3c

Drinking Bird

This toy bird keeps bobbing its head in water because the evaporative cooling and internal pressure differences force the liquid inside above its center of mass, whereupon it tips, momentarily restoring equilibrium.

Vapor Pressure

H-c3d

Hand Boiler

Warmth from your hand forces liquid from the bottom to the top bulb.

Sublimation

H-c4a

Carbon Dioxide Sublimation

A balloon filled with gaseous carbon dioxide is immersed in liquid nitrogen, sublimating the carbon dioxide to a solid and reducing the balloon to its original size.

H-c4c

Dry Ice on Block

Dry Ice and Water Ice are placed on aluminum blocks; the water ice melts to liquid water while the dry ice disappears (slowly...)

Phase Changes: Solid - Solid

H-c4b

Memory Wire (Nitinol)

Heat a bent Nitinol wire with warm water and it springs back to its original shape

Kinetic Theory

Brownian Motion

H-d1a

Brownian Motion - Smoke Cell

The Brownian movement of smoke particles in air is projected onto a screen or wall for all to see.

H-d1b

Brownian Motion Applet

Browning motion java applet: http://www.phy.ntnu.edu.tw/ntnujava/viewtopic.php?t=41

H-d1c

Brownian Motion - Aqueous small spheres

The Brownian movement of small latex or glass spheres in water is projected onto a screen or wall for all to see.

Mean Free Path

H-d2a

Crookes' radiometer

Light shining on the "radiometer" makes the vanes spin, but in a direction opposite to that expected for light absorption and reflection.

Kinetic Motion

H-d3a

Vertical Molecular Motion Simulator

A large disk and a set of small BBs are set into motion by a vibrating plate.

H-d3b

Equipartition of Energy--balls in cup

As this cup of balls is jostled manually with increasing fervor, first the cork, then the polystyrene, and finally the aluminum ball is knocked out.

H-d3c

Equipartition of Energy--vibrating frame

A vibrating frame with two collections of balls differing in mass is used to simulate gases of different molecular weights.

Molecular Dimensions

H-d4a

Monolayer demonstration -- oil putting out flame

A drop of oil puts out the flames of a water/ether mixture

H-d4b

Dust Explosion

Corn starch dust blown into a flame catches on fire.

H-d4c

Diet Coke and Mentos

Drop mentos mints into a bottle of diet coke to produce a geyser

Diffusion and Osmosis

H-d5a

Ink in Water

A drop of ink diffuses slowly in water

H-d5b

Permeable Membrane--sucrose/water

Sucrose solution rises against atmospheric pressure driven by osmotic pressure.

Gas Law

Constant Pressure

H-e1c

Charles' Law--Piston Chamber and Flask

The piston rises and falls depending on whether the flask is heated or cooled.

H-e1a

Balloons in liquid nitrogen

Liquid nitrogen is poured over an air-filled balloon until it collapses.

H-e1b

Helium balloon in liquid nitrogen

Immerse a He balloon successively in graduated pyrex beakers of water and liquid nitrogen to measure its change in volume with temperature at constant pressure

H-e1d

Heat Engine--Piston Chamber and Flask

A mass on top of the piston is lifted when the flask is heated.

Constant Temperature

H-e2a

Boyle's Law--Piston Chamber and Flask

Vary the mass on top of the piston and observe the volume change

H-e2b

Pop Gun

The pop-gun is an example of adiabatic compression

H-e2c

Egg yolk separated from white by vacuum

Separate an egg yolk from an egg white by picking up the yolk with a squeezed plastic bottle.

Constant Volume

H-e3a

Gay-Lussac's Law--Constant Volume bulb

The constant volume bulb is filled with helium at room temperature and pressure, then sealed. It is then immersed in boiling water, ice water, and liquid nitrogen (or in a alcohol/acetone bath).

Constant NUmber

H-e4a

Egg in Milk Bottle

A peeled, hardboiled egg is sucked into a milk bottle when the bottle is cooled, and comes out when the bottle is heated.

Entropy and the Second Law

Heat Cycles

H-f3b

Carnot Cycle Simulation

Carnot Cycle Java Applet: http://www.phy.ntnu.edu.tw/ntnujava/viewtopic.php?t=40

H-f3a

Stirling Engine

An excellent, simple, working model of the Stirling engine.

H-f3d

Stirling Engine on Top of Cup

A Stirling engine on top of a cup of hot water drives a flywheel.

H-f3c

Solid State Heat Engine - Nitinol

A heat engine based on the 60C phase transition of a nitinol wire loop.

Electricity and Magnetism

Electrostatics

Producing Static Charge

EM-a1a

Frictional Electricity

An electroscope is charged using charged rods.

EM-a2c

Party balloon on wall

Rub a balloon against your hair or wool shirt and stick it on the wall.

EM-a2e

Paper pickup with charged objects

Use a comb, PVC rod, glass rod, or other charged object to pick up pieces of paper

EM-a1b

Electrophorus

The top plate of an electrophorus is charged by induction.

Coulomb's Law

EM-a2a

Charged Rods on Pivots

A charged rod on a pivot is used to show attraction and repulsion by another charged rod.

EM-a2d

Large Sphere and Ping Pong Ball

A small charged ball is repelled from a large charged sphere. Attraction and induction can also be shown.

Electrostatic Meters

EM-a2b

Conductive Balls

Two lightweight conducting spheres suspended by nylon thread can be used as charge indicators

Conductors and Insulators

EM-a3a

Conductors and Insulators

Shows that charge can be transferred to an electroscope through conductors but not insulators

Induced Charge

EM-a4a

Electroscope Charged by Induction

Charge an electroscope by induction.

EM-a4d

Inducing Charge -- Two Balls

Two conducting balls in contact are separated in the presence of a nearby charged rod.

EM-a4b

Charged Rods and Aluminum Can

A charged rod can be used to pull a soda can by electrostatic induction

EM-a4c

Deflection of stream of water

A charged rod deflects a stream of water.

Electrostatic Machines

EM-a5a

Wimshurst Machine

Generate sparks with a Wimshurst Machine, and explain its workings.

Electric Fields and Potential

EM-a5b

Van de Graaff Generator

Describe the operation of the Van de Graaff and show sparks from the ball to a nearby grounded conductor.

EM-a5c

Van de Graaff Generator--Sound

The engine strains more and more as the charge on the dome increases.

Electric Fields

EM-b1b

Hair on End

Charge yourself with a Van de Graaff generator

EM-b1m

Van de Graaff stick

Aluminum floaters are held aloft with the Fun Fly Stick

EM-b1c

Styrofoam Peanut Blowout

Styrofoam peanuts in a box on top of the Van de Graaff fly out.

EM-b1e

Tart Pan Blowoff

Tart pans stacked on top of the Van de Graaff fly off.

EM-b1f

Ball Charge Transfer

A conductive ball bounces between electrically charged vertical plates

EM-b1i

Franklin's Bells

A conductive ball bounces between electrically charged bells

EM-b1j

Ball between horizontal charged plates

A conductive ball bounces between horizontal charged vertical plates

Electric Field

EM-b1d

Electric Field Visualizer

Tiny fibers in a clear oil align in the direction of strong applied electric fields.

EM-b1k

Visualizing Field Lines in a Capacitor

Use the Electric Field Visualizer with two parallel conductors to show the field lines for a capacitor including edge effects

EM-b1g

Torque on Electric Dipole

A small rod aligns between parallel plates

Gauss' Law

EM-b2a

Faraday Bucket

Show that charge resides on the outside of a hollow conductor.

EM-b2f

Gauss with Electric Field Visualizer

Tiny fibers in a clear oil that align in the direction of strong applied electric fields remain randomly oriented inside a charged ring.

EM-b2b

Radio in a Cage

Surround a radio by a Faraday cage and the signal goes away

Electrostatic Potential

EM-b3b

Electric Potential -- Parallel Plates

Show that the electric potential varies linearly with distance between Parallel Plates

EM-b3h

Electric Potential -- Point Charge

Show the electric potential variation with distance for a small disk of charge approximating a point charge.

EM-b3a

Surface charge density - conducting balls

A pair of large balls with the same separation as a pair of small balls are charged simultaneously with the Wimhurst.

EM-b3c

Charged Ovoid

Use a proof plane and an electroscope to compare charge densities at different points on an egg-shaped conductor.

EM-b3g

Lightning Rod

Electrical arcing between two large metal spheres abruptly ceases when the lightning rod is touched to one.

EM-b3d

Electric Wind -- Wimshurst

A point attached to a Wimshurst electrode blows a candle flame.

EM-b3f

Electric Wind with Van de Graaff

A point attached to the Van de Graaff blows a hanging piece of cardboard.

EM-b3e

Van de Graaff Pinwheel

A pinwheel rotates on top of a van de Graaff generator.

Force on Moving Charge

EM-b4a

Electron Beam Between Parallel Charged Plates

An electron beam is deflected by the nominally uniform electric field between parallel, oppositely charged plates.(viewing beam from side)

Electric Fields

EM-b4b

Oscilloscope

Show that an electron beam passing between charged, parallel plates is deflected using an oscilloscope (view along beam)

Capacitance

Capacitor

EM-c1a

Parallel Plate Capacitor and Electroscope

Vary the spacing of a parallel plate capacitor attached to an electroscope.

EM-c1b

Rotary Plate Capacitor and Electroscope

The rotary plate capacitor is attached to the electroscope.

Dielectric

EM-c2a

Parallel Plate Capacitor with Dielectric

Insert and remove a dielectric sheet from a charged parallel plate capacitor attached to an electroscope.

EM-c2c

Force on a dielectric

Mineral oil climbs in the gap between parallel plates

EM-c2b

Dissectable Capacitor

This curious capacitor is charged, disassembled, passed around, assembled, and discharged with a spark.

Energy Stored in a Capacitor

EM-c3a

Explosive Capacitor Discharge

Discharge a 10kV, 1uF capacitor through a thin wire or thick screwdriver

EM-c3b

Bulb and 1 Farad Capacitor

A large (1 Farad) capacitor is charged with a battery then discharged through a light bulb.

EM-c3c

Bulb and 1 Farad Capacitor with DVM

A large (1 Farad) capacitor is charged with a battery then discharged through a light bulb, with output monitored with DVM

EM-c3d

Bulb and 1 Farad Capacitor with Oscilloscope

A large (1 Farad) capacitor is charged with a battery then discharged through a light bulb, with output monitored with an oscilloscope.

Resistance

Resistance Characteristics

EM-d1a

Wire Resistivity

Place 6V across a set of wires of different diameters and measure the currents.

Resistivity and Temperature

EM-d2a

Change of Resistance with Temperature

A coil in series with a lamp is immersed in liquid nitrogen making the lamp glow brighter.

EM-d2b

Carbon Resistor in Liquid Nitrogen

Drop a resistor in liquid nitrogen and measure its resistance.

EM-d2c

Conduction in Glass

Heat a glass rod with a flame until its resistance is low enough to sustain conduction.

Conduction in Gases

EM-d4a

Jacob's Ladder

An arc rises between rabbit ear electrodes attached to a high voltage source.

Electromotive Force and Current

Cells and Batteries

EM-e4a

Lemon Battery

Stick copper and zinc electrodes into a lemon and measure the potential difference with a voltmeter

EM-e4b

Internal Resistance of Battery

Measure the voltage across a battery as its load decreases

Thermoelectricity

EM-e1a

Thermocouple

Show a thermocouple in operation

Piezoelectricity

EM-e6a

Piezoelectric Demonstrator

Generate sparks by compressing a piezoelectric crystal.

Other Sources of EMF

EM-e7a

Van de Graaff as emf Generator

Use the grounding wand and a single streamer to show the Van de Graaff generating a constant emf

DC Circuits

Ohm's Law

EM-f1a

Resistor I-V characteristics

Measure and graph the I-V characteristics for a resistor. The value of the resistance may be varied.

EM-f1b

Resistance of a Wire

Measure the potential drop along a wire.

Power and Energy

EM-f1e

Hot Dog Cooker

Spike a hot dog with two nails and cook it.

Circuit Analysis

EM-f2a

Series Circuit with Bulbs

Show a series circuit of light bulbs

EM-f2b

Parallel Circuit with Bulbs

Show a parallel circuit of light bulbs

EM-f2c

Series Parallel Combination

Two bulbs in series with a power supply, and a third bulb in parallel with one of others.

EM-f2d

Effect of resistive wires on circuit

Show effect of resistive wire (here a 10 ohm resistor) leading to a parallel circuit that includes two bulbs and a hairdryer (top photo); bulbs dim when the hairdryer heat is turned on (bottom photo).

RC Circuits

EM-f3b

Lighting bulb with Capacitor

A large (1 Farad) capacitor is charged with a battery then discharged through a light bulb.

EM-f3a

Bulb, 1 Farad Capacitor, and DVM

Monitor the discharge of a 1 Farad capacitor through a light bulb with a digital voltmeter.

EM-f3c

RC Time Constant on Scope--Square Wave

Observe the RC decay from a variable gap capacitor and resistor using a square wave input and oscilloscope.

EM-f3d

Bulb, 1 Farad Capacitor, and oscilloscope

Oscilloscope display of a 1 Farad capacitor discharging through a light bulb.

EM-f3f

Battery Charging Capacitor with Bulb Indicator

Examine the behavior of a light bulb in series with a battery charging up a capacitor.

EM-f3g

Battery Charging Capacitor Bulb Indicator, var. II

Examine the behavior of a light bulb in series with a battery charging up a capacitor.

EM-f3e

Capacitors in Series and Parallel

Discharge a 0.1F capacitor through a light bulb, and compare with that for three in series and three in parallel

Magnetic Materials

Magnets

EM-g1c

Buzz Magnets

A pair of hematite magnets; throw them up separately and they'll combine with a buzz.

EM-g1a

Lodestone

Show that the lodestone attracts small nails and paperclips.

EM-g1b

Steel Bar and Magnet Puzzle

Given only a cylindrical magnet and a similarly shaped steel bar, figure out which is which!

EM-g1d

Gauss Rifle Linear Accelerator

A chain of magnets in gauss-rifle arrangements accelerates a steel ball

Magnet Domains and Magnetization

EM-g2c

The Barkhausen Effect

Clicking noises are heard when a magnet is brought near iron wire within a pickup coil.

EM-g2d

Magnetic Domains in Ferrimagnetic Garnet

Watch a ferri-optical garnet between crossed Polaroids on a microscope as a magnet is brought near.

EM-g2a

Magnetic Domain Model

An array of small compasses shows domain structures

EM-g2b

Hard vs. Soft magnetic materials

A circular magnetic yoke connecting two wire coils is closed with soft and hard materials

Magnetic Domains and Magnetization

EM-g2e

Ferrofluid Display Cell


EM-g2f

Magnetic Permeability - Jumping Ring Height

The height to which the jumping rings jumps depends on how far the yoke extends

Paramagnetism and Diamagnetism

EM-g3b

Paramagnetic Aluminum

A small aluminum rod suspended by a thread in the gap of a powerful magnet aligns with the field.

EM-g3c

Diamagnetic Glass

A small glass rod suspended by a thread in the gap of a powerful magnet orients transverse to the magnetic field.

EM-g3e

Floating Diamagnetic Graphite

A piece of diamagnetic graphite floating on water is pushed around by a magnet.

EM-g3a

Paramagnetic Liquid Oxygen

Liquid oxygen condensing from air drips into the gap of a strong magnet

EM-g3d

Diamagnetic Levitator

A small magnet is suspended in mid-air between two diamagnetic graphite disks.

Temperature and Magnetism

EM-g5c

Curie Point Heat Engine

A small loop of nickel-alloy wire attracted to a magnet keeps oscillating as it heats and cools through its Curie point.

EM-g5a

Meissner Effect

Cool a superconductor and it will levitate and float a magnet.

EM-g5b

Hopkins Superconducting Model Maglev Train

A model train with with two superconducting disks cooled by LN2 glides over a track of powerful magnets

Magnetic Fields and Forces

Magnetic Fields

EM-h1c

Dip Needle

A dip needle is used to show the inclination of the earth's field.

EM-h1a

Oersted Experiment on Overhead

Show that current in a wire deflects a compass needle.

EM-h1i

Oersted Experiment - Large Compass

Show that current in a wire deflects a compass needle.

EM-h1d

Magnet and Compass Array -- 2D

A small magnet on top of the magnetic domain model apparatus

EM-h1j

Magnet and Iron Filings Panel - 2D visualization

Iron filings in a viscous liquid sandwiched between plastic sheets show the path of magnetic field lines. Suitable to pass around

EM-h1e

Magnet and Iron Filings -- 3D

A bar magnet surrounded in 3D by a clear acrylic tank filled with a liquid containing iron filings.

EM-h1g

Gap and Field Strength--Electromagnet

Use a Teslameter to measure the field strength in the gap of an electromagnet, varying the spacing and pole piece diameter.

EM-h1p

Measuring Magnetic Fields with Sensor

Use a Vernier magnetic field sensor to measure the field about a wire, a solenoid, or magnet.

EM-h1f

Magnetic Screening

Insert Acrylic, Aluminum, Copper, and Steel sheets between a magnet and a collection of nails

EM-h1h

Magnetostatic Gauss' Rifle

A ball rolling in a groove bumps into an array of magnet-ball-ball, firing off the last ball of the sequence. Single shot (4 balls) and multiple-stage, magnetostatic accelerator versions available.

Fields and Currents

EM-h1k

B-Field due to long straight wire

Iron filings are sprinkled on a plexiglas plate through which a long vertical current-carrying wire passes.

EM-h1m

B-Field due to single coil.

Iron filings are sprinkled on a plexiglas plate through which a single loop of current-carrying wire is mounted

EM-h1n

B-Field due to solenoid

Iron filings are sprinkled on a plexiglas plate through which a current-carrying solenoid is mounted.

Forces and Currents

EM-h1r

Measuring B-Field due to Current-Carrying Wire

Use a magnetic field sensor to measure the magnetic field from a current carrying wire.

Forces on Magnets

EM-h2c

magnetic dipole in external magnetic field

Shows that a magnet is rotated but not displaced by a uniform B field, and displaced, but not rotated, by a grad B field where B itself is zero.

EM-h2f

Torque balance with air bearing magnet

Balance the magnetic torque on a dipole with a gravitational torque.

EM-h2d

Precessing Magnetic Dipole

A magnetic dipole floating in an air bearing precesses in a uniform B field.

EM-h2e

Classical Magnetic Resonance

Rotate a transverse magnetic field to "flip" the spin of a precessing magnetic dipole.

EM-h2a

Magnets on Pivots

One magnet is placed on a pivot. The other is used to attract or repel the first

EM-h2b

Ring Magnets on a Pole

Two or more ring magnets are placed on a vertical pole

EM-h2g

Robby the Seal

A puzzle--how does the seal balance the ball and make the ball rotate when brought near to it?

EM-h2h

Magnetic Ballerina Puzzle

The ballerina twirls when put in front of the mirror; hidden magnets exert the force.

Force on Moving Charges

EM-h3a

e/m tube

Deflect the beam in an e/m tube with magnets

EM-h3b

Oscilloscope and magnet

Deflect the beam in an oscilloscope with magnets

Force on Current in Wires

EM-h4a

Force Between Two Current Carrying Conductors

Show on the overhead projector that long parallel wires with currents in the same (opposite) directions attract (repel).

EM-h4c

AC and DC Lamps

A magnet is brought near two carbon filament bulbs, one DC powered and one AC powered.

EM-h4b

Force on Current-carrying wire

A loop of wire swings to the side of a U-magnet's gap when connected to a current-limited power supply.

EM-h4e

Jumping Wire

A length of wire jumps out of the gap of a U-magnet when connected to a current-limited power supply or battery.

EM-h4d

Rail Gun -- External Magnet

A wheel and axle accelerate along two electrified rails over strong rare-earth magnets

Torques on Coils

EM-h5a

Galvanometer

A magnet exerts a torque on a current-carrying coil.

Inductance

Self-Inductance

EM-j1b

Back EMF with light bulb

A light bulb in parallel with an inductor flashes when its power is disconnected.

EM-j1a

Inductance Spark--Large Electromagnet

A bright spark is produced when the switch of a large electromagnet is opened

EM-j1c

Inductance Spark -- classroom version

A bright spark is produced when an inductor is disconnected from a power supply

LR Circuits

EM-j2a

Series RL circuit: L/R charge/discharge

"Charging" and "Discharging" of inductor shown with square wave and oscilloscope

EM-j2b

Series RL circuit: L/R phase shifts

Show phase shifts in a series RL circuit using the oscilloscope.

EM-j2c

Variable Inductor

A lamp in series or parallel with a variable inductor.

RLC Circuits - DC

EM-J3a

non-driven LRC circuit oscillations

Show the oscillations (ringing) when a charged capacitor is connected in series to an inductor and small resistor.

EM-J3b

non-driven RLC ringing with audio

A battery "charges" a capacitor and inductor in parallel; when disconnected, the resulting induced ringing current is shown on an oscilloscope and heard through a speaker.

Electromagnetic Induction

Induced Currents and Forces

EM-k1g

Sliding bar in magnetic field

A bar sliding on rails over a bed of magnets generates an emf along the bar.

EM-k1a

Induction Coil and Magnet

A magnet is moved in and out of a coil connected to a galvanometer

EM-k1c

Loop rotating in magnetic field

A loop of wire is rotated in in the gap of a permanent magnet.

EM-k1d

Pickup Coil and Magnet

A magnet is moved in and out of a coil connected to a galvanometer

EM-k1e

Audible Pickup Coil

Generates sounds in a pickup coil connected to a speaker with a steel tuning fork.

EM-k1b

Induction with Coils and Battery

Attach one coil to a galvanometer, another to a battery and tap switch. Use a core to increase coupling

EM-k1f

Current Coupled Oscillators

A magnet suspended by a spring inside a wire coil induces oscillations in a second magnet that is spring-suspended over a second coil.

Eddy Currents

EM-k2a

Eddy Current Pendulum - Lecture Hall

A copper sheet, a comb, a ring, and a broken ring are swung through a large electromagnet.

EM-k2f

Eddy Current Pendulum -- Classroom

Swing solid. open-slotted, and closed-slotted paddles between the poles of a neodymium magnet.

EM-k2b

Magnets and Eddy Tubes

Drop magnet and a non-magnetic dummy down an aluminum tube.

EM-k2c

Magnet and Copper Tube

Drop magnet down a short length of straight copper tubing and watch it fall.

EM-k2h

Pushing and Pulling Ring with Magnet

Push and pull a solid aluminum ring suspended from strings; a split ring is provided for comparison.

EM-k2i

Magnet Pushing and Pulling Ring - Small Version

Push and pull a solid aluminum ring suspended from strings; a split ring is provided for comparison.

EM-k2d

Jumping Rings

A solid conducting ring sitting on a vertical solenoid jumps and a split ring doesn't

EM-k2e

Eddy current levitator

A strong ceramic magnet is levitated over a spinning aluminum disc.

Transformers

EM-k3b

Dissectable Transformer

Light a bulb and show voltage relationships with various coil and frequency combinations.

EM-k3a

Transformer

Demonstrate step-up and step-down transformers.

EM-k3c

Lines of Current with Clamp-On Ammeter

Measure and count lines of current with a commercial clamp-on ammeter.

Motors and Generators

EM-k4e

Handheld DC Motor

Run the handheld DC generator with a 1.5 or 3 V battery

EM-k4a

AC Generator/Motor

Rotating a wire loop in a magnetic field by hand generates an AC current; it can be driven by connecting it to a function generator.

EM-k4b

DC Generator

Generate a DC current by rotating a loop with a split-ring connection in a magnetic field.

EM-k4c

Direct Current Motor

Show and explain a DC motor running on batteries.

EM-k4h

Induction Motor - Disassembled Fan

An aluminum ball rotates in the center of a coil-created rotating magnetic field.

EM-k4g

World's Simplest Motor

A simple DC motor that requires only a battery, a bare wire, a nail, and a magnet.

EM-k4d

Hand-held DC Generator

Use the handheld generator to illuminate a bulb.

EM-k4f

Hand-powered flashlight

The Dynamo--a hand powered flashlight

Eddy Currents

EM-k2g

Induction Flashlight

This flashlight runs on induction-induced currents, a capacitor, and an LED lightbulb.

AC Circuits

LRC Circuits--AC

EM-L2a

60 Hz LRC circuit

Shows the potential difference across the Capacitor and Inductor at resonance.

EM-L2b

LRC circuit with function generator

Show the relative phases and amplitudes for the potential differences across the components of an driven LRC circuit.

EM-L2d

RC Circuit -- Phase relations

Show the potential difference across the power supply, the resistor, and the capacitor as a function of frequency, resistance, or capacitance.

EM-L2e

RL Circuit -- Phase relations

Show the potential difference across the power supply, the resistor, and the inductor as a function of frequency, resistance, or inductance.

EM-L2f

driven LRC circuit at resonance

Compare the aplitudes of the power supply voltage to the voltage over the capacitor at resonance. Note the phase shift.

Filters and Rectifiers

EM-L3a

Bridge Rectifier with LEDs

Operate a bridge rectifier with LEDs at low frequency

Semiconductors and Tubes

Semiconductors

EM-m1b

Hall Effect

Measure the transverse potential difference between between the sides of silver or tungsten in crossed electric and magnetic fields

Diode

EM-m1a

Diode I-V characteristics

Circuit for measuring the I-V characteristics of a diode

Electromagnetic Radiation

Transmission Lines and Antennas

EM-n1f

Model Transmission Line

Show-and-Tell model of a transmission line.

EM-n1g

Coaxial Cable Samples

Coaxial cable samples to pass around

EM-n1d

Propagation Velocity in Coaxial Cable

To show and measure the finite velocity of an electromagnetic pulse in a length of coaxial cable.

EM-n1e

Reflections in Coaxial Cable

Show the reflected pulse in a 50 ohm coaxial cable terminated with an infinite, 50 ohm, and zero ohm impedance.

EM-n1c

Microwave Standing Waves

Use a microwave generator, detector, and metal sheet to show standing waves

EM-n1h

Microwave Waveguide - Sample

A sample of microwave waveguide and tubing

EM-n1i

Microwave Waveguide

Roll a steel tube in front of a microwave generator and measure the intensity at the end.

EM-n1a

Radiation from a Dipole

Use a transistor radio to pick up a 100 MHz signal generated by a function generator.

EM-n1m

AM Radio

Modulate the output of a function generator attached to an antenna and detect the output with a transistor radio

EM-n1b

Microwave Generation and Detection

Show the generation and detection of microwaves including polarization

Tesla Coil

EM-n2a

Tesla Coil

Light a fluorescent lamp by holding it near a Tesla Coil

EM-n2c

Large Tesla Coil

Light a fluorescent lamp by holding it near a Tesla Coil

EM-n2d

Plasma Mug

Light up gas inside the mug walls by placing it near a Tesla Coil

EM-n2e

Plasma Ball

Show and Touch the Plasma Ball and draw sparks toward your finger.

EM-n2f

Plasma Disk

Believed to be a plasma screen version of the Plasma Ball

Electromagnetic Spectrum

EM-n3b

Project the Spectrum

Project white light through a high-dispersion prism

EM-n3c

USA Radio Frequency Allocation Chart

Radio Frequency Allocation Chart found at http://www.ntia.doc.gov/osmhome/allochrt.pdf

EM-n3a

Microwave Transmission

Insert different materials (wood, metal, plastic, metal grill of small holes, wet and dry cloths) in a microwave beam

Optics

Geometrical Optics

Speed of Light

O-a1b

Speed of light in fiber optic cable

Compare the time for a light pulse to travel through two different lengths of fiber optic cable.

O-a1i

Speed of Light -- Rotating Mirror Method

Measure the speed of light by Foucault's rotating mirror method

Straight-Line Propagation

O-a1a

Light Bulb in Vacuum

Show a buzzer and light bulb in vacuum

Reflection from Flat Surfaces

O-a1c

Blackboard Optics -- Plane Mirror

Use multiple-beam generator to show image formation with a plane mirror.

O-a1g

Diffuse vs Specular Reflection

Reflect light first from a shiny surface, then from a rough surface.

O-a1j

Diffuse vs Mirror Reflection -- Quantitative

Reflect light off of an acrylic surface into a photometer; repeat with a mirror

O-a1h

Glancing and Normal Reflection

Observe image formation at glancing angles from glass and metal surfaces

O-a1d

Corner Reflector

Look into a corner reflector

O-a1f

3-D axes in Plane Mirror

Right-handed and left-handed coordinate axes illustrate parity reversal in a mirror.

O-a1e

Multiple Virtual Images

By folding two mirrors hinged together, show multiple virtual images of a candle.

Reflection from Curved Surfaces

O-a2c

Blackboard optics -- curved mirrors

Show image formation (size, location, orientation) from concave and convex mirrors on the blackboard.

O-a2d

Optic Mirage

Two concave mirrors face each other. The top mirror has a hole allowing light to enter and escape. An image of the objects resting on the bottom of one appears at the center hole of the top mirror.

O-a2e

Large Concave/Convex Mirrors

Shake hands with yourself using the large concave mirror; view images in the large convex mirror.

O-a2f

Large Concave/Convex Mirrors -- on Stand

Alternative pair of concave/convex mirrors

Refractive Index

O-a4a

Magic Mending Solution

A broken pyrex beaker is "magically" mended with a beaker of Wesson Oil.

O-a4b

Schlieren Images of Gases

Blow hot air, light a bic lighter, and/or pour SF6 or CO2 in front of a concave mirror
in a Schieren arrangement.

Refraction at Flat Surfaces

O-a4d

Refraction with Blackboard Optics

A single beam of light shines on a large acrylic surface.

O-a4j

Stick in Water

A stick appears bent when inserted into the water at an angle.

Total Internal Reflection

O-a4s

Total Internal Reflection (Blackboard Optics)

Show total internal reflection with the blackboard optics kit.

O-a4p

Total Internal Reflection-Fiber Optics

Shows the path of a laser beam inside an acrylic rod.

O-a4q

Optical Fibers

Show (with a laser pointer) and tell with optical fibers

O-a4r

Fiber Optic Image Conduit

An image is spatially displaced with an image conduit.

O-a4t

Water Stream of Light

Shine a laser beam through a tank of water and out through a hole through the side.

Thin Lens

O-a6a

Blackboard Optics -- Thin Lens

Ray trace images using convex and concave lens and a parallel ray box.

O-a6b

Image formation with Thin Lens

Project or view the image of an illuminated arrow through a thin lens.

O-a6c

Magnifying Glass with Eye Model

Use the Working Eye Model to show a magnifying glass enlarging an object's image and allowing the near point to move closer to the eye. Greater magnifications can be achieved with stronger magnifiers.

Thick Lens

O-a6p

Chromatic Aberration

Show chromatic aberration using a large lens and an iris diaphragm.

O-a6q

Pincushion/Barrel Distortion

Show pincushion and barrel distortion with a thick lens and grid object.

O-a6r

Astigmatism

Rotate a lens that is imaging a point light source to show astigmatism

O-a6s

Coma

Rotate a lens that is imaging a point light source to show coma

O-a6u

Spherical water lens

Project an image with a water-filled spherical flask

O-a6t

Fresnel lens

Look through a Fresnel lens

Optical Instruments

O-a7e

Two-Lens Microscope Model

Use two lens to make a simple compound microscope.

O-a7f

Phase Contrast Microscopy

Show cheek cells (epithelial) in bright field and phase contrast views.

O-a7g

DIC (Differential Interference Contrast) Microscopy

View cells and diatoms with a microscope adjusted for differential interference contrast.

O-a7a

Microscope Model (Blackboard Optics)

Mimic a microscope objective with blackboard optics.

O-a7b

Telescope Model

Use two lens to make a simple telescope.

O-a7d

Celestron Telescope

Show and tell the Celestron C90 telescope with Maksutov-Cassegrain optics, 90 mm aperature, 1 m focal length, and f/11 focal ratio.

Photometry

Blackbodies

O-b4b

Blackbody Radiation - Infrared Camera

Examine objects in a dark room with an infrared camera

O-b4a

Blackbody Radiation

Project the spectrum of an incandescent bulb as a function of temperature.

Diffraction

Diffraction Through One Slit

O-c1a

Single Slit Diffraction Pattern - Cornell Slits

Shine a laser beam through single slits of various widths. The Cornell slitfilm is shown; we also have a slitfilm from Pasco

O-c1b

Microwave Diffraction - Single Slit

The diffraction pattern of a single slit can be heard with the audio-coupled detector

Diffraction Around Objects

O-c2a

Arago's (or Poisson's) Spot

The diffraction pattern from a laser beam shining on a small ball has a bright dot in the center of the shadow of the ball.

O-c2e

Pin hole diffraction - projected

View the diffraction pattern of a pinhole; a variety of pinhole dimensions are available. The photo shows 100 um and 50 um round pinhole patterns and 100 um and 50 um square patterns.

O-c2c

Pin hole diffraction - pass around version

Look through a pinhole at a bright point light source to see Airy rings.

O-c2d

Rayleigh Resolution Limit (pass around)

Look through a succession of pinholes of increasing aperture size at a pair of bright point light sources.

O-c2b

Fresnel zone plate

Shine an expanded laser beam at a Fresnel Zone plate and look at the diffraction pattern

Interference

Interference from Two Sources

O-d1a

Double Slit and Laser - Cornell Slitfilm

Use a laser bean on the slits on the far column of the Cornell slitfilm to show the effect of increasing the spacing between a pair of slits, with the slit spacing held constant. The first entry is a single slit.

O-d1d

Double Slit and Laser - Pasco 2-slit slide

Any pair of the four sharply defined double slit patterns on the Pasco slide produces a nice and extended double-slit pattern when illuminated by a laser beam.

O-d1b

Microwave Double Slit Interference

Placing the Aluminum Sheet with Double Slit in front of the Microwave Generator produces a double slit interference pattern which can be detected by the Microwave detector and heard through the auditorium.

O-d1c

Coherence Length -- Slitfilm

A Cornell slitfilm and microscope slide are used to show that the coherence length of white light is short compared to laser light.

Gratings

O-d2b

Rowland Ruling Engine

The Rowland Ruling Engine, on the second floor of the Bloomberg Center.

O-d2a

Number of Slits

Shine a laser beam through various numbers of slits with the same spacing and width

O-d2c

Types of Diffraction Gratings

Transmission and Reflection, Blazed and Not, Diffraction Gratings of different line densities probed by a laser.

O-d2g

Grating, Laser, and Mist

Use mist to illuminate the beam of a red and then green laser, and then insert a diffraction grating into the beam.

O-d2h

Diffraction from CDs and DVDs

Light is diffracted from a CD and DVD

O-d2e

2D Diffraction - Pasco Patterns

Show diffraction patterns from two 2D patterns, one square in symmetry and one hexagonal.

LO-d2j

Diffraction from Rabbit Muscle

A setup for examining the diffraction from the striations in rabbit muscle.

LO-d2k

Diffraction from Butterfly Eye

A setup for examining the diffraction from a butterfly's eye.

O-d2i

Holiday Lights and Bulbs

Look at a string of small light bulbs with double-axis grating glasses

O-d2j

1D Lattice with Basis - optical crystal

Diffract laser light from a grating with secondary ("basis") gratings shifted by 0, 1/4, 1/2, and 3/8 of a period of the fundamental 0.30mm "lattice spacing."

O-d2d

2D Diffraction - Optical Transform Kit

Diffract laser light with this set of 32 patterns, mostly of 2-D lattices with various symmetries and lattice bases, available from http://ice.chem.wisc.edu

O-d2f

2D Diffraction - DNA Optical Transform

Use this set of 12 grating patterns with a laser to teach the diffraction of DNA (slide also available from http://ice.chem.wisc.edu)

Thin Films

O-d3a

Newton's Rings

Reflect white light off Newton's Rings onto a screen.

O-d3b

Soap Film -- 2 Litre Bottle

View the interference fringes of a soap film in a 2-litre bottle.

O-d3c

Bubbles

View large soap bubbles under white light illumination.

O-d3d

Air Wedge

Two microscope slides on top of one another produce interference fringes between them.

Interferometers

O-d4a

Michelson Interferometer

Show the Michelson Interferometer and how it works.

O-d4b

Michelson Interferometer and soldering iron

Produce an interferogram of turbulant air with a soldering iron in the optical path of the Michaelson interferometer.

O-d4c

Michelson Interferometer -- real vs. virtual fringes

Compare the virtual interference fringes formed from a planar light source with real fringes from a point light source

O-d4d

Michelson Interferometer -- Fizeau fringes

Inclining the mirrors of the interferometer with respect to each other produces straight fringes

Color

Synthesis and Analysis of Color

O-f1a

Spinning Color Sticks

Red, green, and blue lightsticks in a fan arrangement produce white when spung.

O-f1b

Glow Ball

Spinning the Glow Ball produces red, blue and green streaks whereas it appears whitish when not spun.

Scattering

O-f4a

Sunset

A beam of light shines through a tank of slightly milky water onto the wall.

Polarization

Dichroic Polarization

O-h1a

Polaroids on the Overhead

Show polarization with two or three sheets of polaroid on the overhead

O-h1d

Vanishing Wall

Put your hand through a "wall" created by a trick of polarization.

O-h1b

Microwave Polarizing Filter

Insert a grid of parallel wires (= cookie cooling rack) in a microwave beam and rotate the grid.

O-h1c

Polarization - Mechanical Model

Use a grid of parallel wires (= cookie cooling rack) with a vibrating string as a mechanical model for polarization.

Polarization by Reflection

O-h2b

Reflection off Water

Reflected light is shown to be polarized.

O-h2a

Microwave Brewster's Law

Show that microwave radiation after reflection is polarized.

Circular Polarization

O-h3a

Karo Syrup

Insert a beaker of liquid sugar between crossed polaroids.

Birefringence

O-h3p

Calcite Crystals

Use a polaroid filter to show the polarization of ordinary and extraordinary rays

O-h3q

Demonstrating Strain with Crossed Polaroids

A set of lucite shapes are stressed between crossed polaroids

Polarization by Scattering

O-h5a

Polarization in the Sunset Demo

Rotate a Polaroid at the side of the tank in the sunset demo.

The Eye

The Eye

O-j1d

Molded Eye Model

Show a molded model of the eye.

O-j1g

Giant Eye in Bony Orbit Model

Show a take-apart model of the eye.

O-j1c

Working Eye Model

A model demonstrates the focal capabilities of the normal, nearsighted, and farsighted eye.

O-j1e

Eye Model (Blackboard Optics)

Show normal, nearsighted, and farsighted blackboard optics eye models, and correct with additional lenses.

Physiology

O-j1f

Haidinger's Brush

Detect the polarization of light by observing Haidinger's brush at the center of a bright white screen.

O-j1a

Purkinje Figures

Use a penlight under the eye to make the blood vessels in front of the retina visible.

Modern Optics

Physical Optics

O-q2a

Aperture in back focal plane - laser light

Use a laser and convex lens to project an image of a grid, and show the decrease in sharpness of the grid's image as the aperture of an iris located at the lens' back focal plane is decreased.

O-q2b

Aperture in back focal plane - white light

View the image of a grid in white light, while reducing the aperture in the lens' back focal plane.

Lasers

O-q6a

HeNe Laser exposed

Examine an exposed operating HeNe laser cavity with a diffraction grating.

O-q3c

1W Laser Burning through Materials

Burn holes in wood, paper, and plastics with a 1W 405nm laser

O-q3b

Transmitting Sound with Laser

Modulate the input voltage to a laser pointer with an ipod and use a photocell and speaker to play the sound.

Modern Physics

Quantum Effects

Photoelectric Effect

MO-a1a

Photoelectric Effect in Zinc

A charged electroscope attached to a zinc plate discharges when UV light illuminates the zinc.

MO-a1b

Photoelectric Effect in Cs-Sb photocell

Plot the stopping potential for various LEDs shining on a Cs-Sb photocell; the intensity versus bias potential may be plotted as well.

Wave Mechanics

MO-a5d

Vibrating Circular Wire

A circular wire driven by a function generator produces standing waves at resonant frequencies.

Wave Particle Duality

MO-a5e

Video: Single-Photon double slit interference

A camera records the interference pattern due to photons entering a double-slit a single photon at a time.

X-ray and Electron Diffraction

MO-a6a

Electron Diffraction

Electrons passing through a carbon target produce a circular diffraction pattern.

Liquid Helium

MO-a7a

Movie--The Unusual Properties of Liquid Helium

Isadore Rudnick's 1977 film, 16 minutes long, focusing on many spectacular properties of liquid helium. Transcript available.

Atomic Physics

Spectra

MO-b1a

Diffraction Grating and Atomic Spectra

Have students look through a diffraction grating at a spectrum tube.

MO-b1d

Atomic Spectra Poster

Poster with atomic spectral lines of Li, Na, K, Ca, Sr, Ba, Zn, Cd, Hg, H, He, Ne, Ar, and Carbon along with the some common absorption lines.

MO-b1f

Diffraction Grating on Webcam: RSpec

Display both spectral lines and an intensity plot with a grating-covered webcam.

LMO-b1e

Prism Spectrometer

Have students look through a prism spectrometer at a sodium lamp.

Absorption

MO-b1b

Spectrum of Sun

Point the spectrometer at the sun to see the Fraunhofer absorption lines.

Resonance Radiation

MO-b1c

Fluorescent Materials

Illuminate various fluorescent materials with UV light.

MO-b1e

Quantum Dots - InP solution

Four vials of InP quantum dots of different diameter fluoresce with different colors under violet light

MO-b2a

UV detecting beads

Put "Ultraviolet Detecting Beads" from Educational Innovations under UV light and they become colorful. Unique Mechanism.

Electron Properties

MO-b3a

Maltese Cross

A photon shadow is not effected by either an electric or a magnetic field, but an electron shadow is.

Nuclear Physics

Radioactivity

MO-d1b

Geiger Counter and Samples

Listen to the counts from a Geiger Counter brought near to a radioactive sample.

MO-d1a

Muon Lifetime

Over the course of a few hours the Teachspin Muon Physics apparatus detects sufficient muon decays to make a rough estimate of the muon lifetime.

Particle Detectors

MO-d3b

Open-air Alpha Particle Spark Detector

Sparks fly from a wire grid to a high voltage plate when alpha particles are present.

MO-d3a

Diffusion Cloud Chamber

A diffusion cloud chamber shows the tracks from cosmic rays and from alpha, beta, gamma, and X-ray sources.

Elementary Particles

Miscellaneous

MO-e1a

Video: Large Hadron Rap

The Large Hadron Rap video

Astronomy

Planetary Astronomy

Solar System Mechanics

A-a1a

Orrery model

A motor driven mechanical model of all the planets.

Stellar Astronomy

The Sun

A-b1a

Solar telescope

Observe solar flares, prominences, filaments, and sunspots directly with a dedicated telescope with built-in hydrogen alpha filter. We have two telescopes (Coronado PST and Lunt LS50THaPT).

A-b1b

Observing Sunspots - Sunspotter

Project an image of the sun, with sunspots and flares, on the screen of the Sunspotter

Cosmology

Models of the Universe

A-c1a

Expanding Universe

Pull a rubber hose threaded through five styrofoam balls.

Black Holes

A-c2a

Membrane Table

A heavy mass sitting on fabric stretched across the vortx models a black hole in space-time.


Physics Lecture Demonstrations at the Department of Physics and Astronomy
The Johns Hopkins University