Author: aneat1

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Rspec Explorer Camera

Rspec camera aimed at spectral tube and LED tower

Hydrogen emission spectrum, as viewed with Rspec software.

LED tower spectrum, as viewed with Rspec software.
  • The Rspec Explorer is a web cam with diffraction grating attached. A live image, or previously acquired pictures of a spectrum can be viewed and shown to a class, and features explained and analyzed.
  • The Rspec software (shown above) allows for spectral analysis, and can be downloaded here: https://www.fieldtestedsystems.com/GetRex/. As long as the camera is plugged into your computer, a software license passcode is not required. Both mac and pc versions are available. 
  • Some useful instructional videos can be found here: https://www.fieldtestedsystems.com/videos/
  • The LED tower (shown in top photo above, next to spectral tube) contains 11 different LED’s of various wavelength, and pairs well with the camera as a demo.
  • Located in L35, Isle G, top shelf, next to diffraction gratings.
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Dynamo

  • Use a power supply (not shown) to run current through the 0.1m coils. Use the power supply shown to spin up disk to approx. 4000 rpm (Mike Brown can tell you how to determine the rpm). A potential difference between the outer rim of the wheel and the axel is induced and can be measured using a voltmeter.
  • Located in storage room, L-50.

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Galton Board

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 Galton3 Galton2

  • Explore the physics of Plinko with this demo… and the Normal distribution.
  • Small bbs fall through a plinko board, randomly, and are forced into columns (binned). The number of bbs per column, statistically, should approximate a normal distribution.
  • The mathematics of Pascal’s triangle can also be discussed. See below youtube link.
  • Located in L02, section C3.

 

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Cycloid Ramp

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cycloid ramp2

  • The amount of time required for a rolling ball to reach the bottom of a cycloid ramp is, surprisingly, height independent. Test this out by releasing two balls, simultaneously, from two different heights along the ramp (bottom picture). Balls always collide at the lowest point where the two ramps meet. Place the metal tube on the ramp, at lowest point, to allow students to hear the simultaneous clang made when balls reach bottom.
  • The  Brachistochrone problem can be discussed by showing that a ball travels more slowly down an un-curved ramp than it does down a cycloidal one.
  • Numbers along curve indicate height from bottom.
  • Located in L02, section B2.
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Water Hammer

water hammer

 

  •  The water-containing flask has been partially evacuated, allowing the water inside to fall as one solid column. (Typically water breaks up as it falls through air, due to drag.) The sound made when the water hits the bottom is quite remarkable.
  • To use: hold the flask vertically with the bulb at the top. Quickly shake the flask up and down once. When the water hits the bottom it sounds (and feels!) more like a solid metal object than a fluid.  In fact, I’m convinced that the flask would break if shaken hard enough, though the information sheet doesn’t caution against it.
  • Located in L02, section D1.

 

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Mixing red and green lasers

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Shine red and green laser light into fiber optic simultaneously to produce yellow.

Lasers need to be aimed appropriately to obtain the optimal ratio of red to green (aim green less directly than red, as green laser is brighter).

Location

  • Fiber optic and lasers in Lo1, section B5 and B6.

 

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Penguin Circuit

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  • Toy can be used to model (by analogy) a simple DC circuit.
  • Penguins represent charges.
  • Track represents wires.
  • Escalator represents battery.
  • It’s a little goofy, but audiences love it.
  • Located in Lo1, section B3.
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Perpetual Top

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  • Top contains motor and off-balance rotor with rotational wobble.
  • The wobbling rotational impulse provides top impetus to spin in clockwise direction. For additional info, see: P3-3503_DS.
  • Top also contains a red/green/blue LED. Persistence of vision mixes primary colors as top spins, allowing eye to see various secondary colors depending on LED flashing pattern.
  • Located in L03, section D4.

 

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Dropper Popper

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  • The “Dropper Popper” bounces about 2 meters high, no matter what height it is released from.
  • The rubber half-sphere (as seen on left, in above image), can be turned inside out (as seen on right). Stored energy is instantly released when popper turns right-side-out; and, if resting on a flat surface, will launch about 2 meters high. To trigger this, popper must be dropped, flat, onto a hard surface.
  • Hold and release popper as shown in top image, away from body.
  • If having difficulty dropping it perfectly flat, spin it like a frisbee while releasing.
  • Located in L02, section B4.
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Bernoulli Bag

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  • 8 ft long bag requires many dozens of breaths to inflate if held directly to the mouth.
  • But when bag opening is held a short distance from mouth, bag can be inflated with one breath.
  • Bernoulli’s principle can be used to explain how a current of swift moving air can pull a large volume of air along with it. See: P6-7350_DS
  • Located in L02, section D1.
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Cartesian Diver

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  • Floating squid-looking object sinks when bottle is squeezed.
  • Squid contains a plastic pipette, partially filled with air. When the bottle is compressed the pipette experiences an increase in external pressure, causing the volume of air inside  the pipette to decrease. This decrease in volume reduces the squid’s buoyancy, and squid sinks.

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  • Located in Lo2, section D2.
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Victorian Bulb

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  • The Victorian light bulb (a replica of Thomas Edison’s original design) contains a long, visible, carbon filament.
  • When a neodymium magnet is brought into close proximity of the bulb, the field of the magnet causes the filaments to vibrate at 60 Hz (the frequency of AC current in the filaments).

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  • Bulb located in L01, section B3 (in a small, labeled box).
  • Lamp cord in L35, section D2.
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Missing Arago Spot

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  • This demo is meant to illustrate what would happen if photons behaved like classical particles, or bb’s.
  • Bb’s act as photons, and circular platform acts as a “light” barrier.
  • With paper and carbon paper under the platform, pour the bb’s onto the platform. BB’s will scatter off and make marks on the paper underneath the platform where they hit. Spoiler alert: They don’t make an Arago spot.
  • Use funnel to obtain uniformly vertical stream.
  • Copper sheet provides hard, low-bounce surface. Long cardboard box, located next to demo, in L01, can be used to prevent scattering of bb’s across table surface.
  • Demo Located in L01, section C1.
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Equivalent descent time

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  • Right triangle shown above is made of taut string.
  • Each side contains a brass ball that is free to slide along the string segment.
  • Time of descent, from top to bottom of segment, is equivalent for each of the three balls.
  • This is true for any right triangle, with vertical hypotenuse,  as the side lengths are reduced by the same factor as the rate of acceleration.
  • String is mounted on white-board material so instructor can derive equations alongside triangle using a dry erase marker.
  • Located in L02, section B3
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SpillNot

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  • The SpillNot allows for rapid, spill-less, acceleration of a liquid-carrying container.
  • Place cup on flat base and carry gadget by flexible loop handle.
  • Rapid turns and sudden changes in motion should produce no spilling.
  • Practice before use in class.
  • Located in L02, section B2.
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g ball

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  • Ball can be used to measure the free-fall time of an object.
  • Release of a button on ball’s face starts a digital timer. Timer automatically stops upon collision.
  • Please use a landing cushion, such as the styrofoam pad shown above, to prevent the risk of cracking face of digital timer.
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Human Arm Model

human arm model

arm model 2

  • Human arm model can be used to show how muscle tension in bicep (or tricep) relates to magnitude of force on hand, in various orientations.
  • Picture above shows how 12 N of muscle tension are required to hold a mass weighing 1 N, in the hand, when the forearm is held at a 90 degree angle.
  • Model allows for several different configurations and activities. See: https://www.pasco.com/prodCatalog/PS/PS-2611_human-arm-model/index.cfm
  • Located in L02, section B4.
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Driven Pendulum

driven pend 2

driven pend

  • Tap pendulum repeatedly with pool noodle (pink thing). If tapping frequency matches swinging frequency, amplitude of swing will increase and become very large. If tapping frequency is too high or too low (i.e., does not match swing frequency), swing amplitude will remain small.
  • Pendulum and noodle located in L02, section C1. Ring stand in L35, section A.
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Unmixing demo

unmixing 2

  • The gap between two concentric transparent cylinders is filled with glycerin. A handle attached to the inner cylinder allows the inner cylinder to be rotated smoothly.
  • Dyed glycerine (red, blue, and/or green) is injected into the clear glycerine using the syringes shown.
  • After the dyed glycerine is injected, the inner cylinder can be turned several times, causing the dyed regions to mix and disappear.
  • Surprisingly, turning the inner cylinder backwards, the same number of turns, unmixes the dyes and brings them back to their original appearance and location.
  • Inner cylinder is filled with water (to keep it from floating) creating index matching between the cylinders, and causing the inner cylinder to completely disappear.
  • Video of this apparatus in use:https://youtu.be/cTek7WN4AD4
  • Demo is located in L35. Glycerine can be reused several times before replacement is required.
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Laser light bend

laser bend

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  • Tank shown above contains a solution of sugar water that becomes more and more concentrated with depth. As sugar water has a higher index of refraction than pure water, the sugar density gradient produces a depth-dependent index of refraction. A laser beam shot through the solution, initially parallel to the bottom of the tank, will bend downward and hit the bottom.
  • To prepare solution: pour sugar into empty tank, a few centimeters thick. Then, using a hose, very slowly (so as not to agitate sugar) fill the tank with water about halfway full.
  • Tank located in L01, section B6. Sugar in L35, under sink. Laser in L35, section A5.
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Air flow lift

Bernoulli effect

 

bernoulli 2

  • When air is blown over the top of a piece of paper, reduction of air pressure creates lift, causing paper to levitate.
  • Fan located in L02, section B4
  • Paper with rod located in L02, section D1
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Air-flow levitation

Bernoulli's Principle levitation 1

Bernoulli's Principle suction 1

Bernoulli's Principle suction 2

  • Air-flow around ball causes nonintuitive levitation and stability.
  • A nozzle connected to the air-blower creates a narrow stream of fast moving air.
  • Ball can be levitated directly above air nozzle, or at an angle.
  • When funnel is connected to air hose, air flow around ball creates lift, preventing ball from falling, even when air flow is directed downwards.
  • Blower, nozzle and funnel located in L35. Ball in L02 section A2.
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Boomwhackers

boomwhackers

  • Length of each tube determines tube’s resonance pitch. The longer the tube the lower the pitch. Tone produced by whacking a tube reveals its note of resonance. Resonance pitch can be changed by attaching the plastic end-cap.
  • For additional demo ideas and see: boomwhackers
  • Located in L02, section C2.
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Whistling Whirly Tubes

 

whirly tube

  • Hold handle-side of tube securely and twirl around rapidly in a circle. Tube makes a whistling sound that can be heard long distances, resulting from standing pressure waves that set up in the tube. Pitch of whistle depends on twirling speed, however, because only standing waves produce a whistle, the pitch of the whistle goes from one octave to the next in discrete jumps. See: sound pipe document for further explanation.
  • Can also use tube to demonstrate Bernoulli’s principle. Pressure difference between tube ends results from faster motion of outer end. Pressure differential produces air flow through tube. Stationary end of tube (handle end) acts as a vacuum and will suck up small pieces of paper when outer end is twirling.
  • Located in L02, section C2.
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Polarization (outreach set)

polarization

Demos in this set include:

  • Planar light source with large polarizing sheet
  • Corn syrup
  • Long spring
  • Plastic fork
  • Wafers of micah and benzoic acid crystals
  • Cubes of calcite, selenite, and Iceland spar
  • Disappearing cube
  • Polarizer model (looks like a gate), with light model (wavy wire piece)
  • Square and circular polarizers
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Measuring h with LED

measuring H1

How to measure Planck’s constant using an LED

  • Measure LED threshold voltage using voltmeter and ammeter.
  • LED converts electron energy to photons. Energy lost by electron = energy gained by photon = (electron charge) times (voltage).
  • So, if threshold voltage is 2.2 volts, energy of emitted photon must be 2.2 eV.
  • Use  E=hc/lambda, and measure lambda using Red Tide spectrometer with Logger Pro (see below pic), to determine h. Take data using LEDs of 4 different colors and fit data to line with slope h.
  • Hand held spectrometer can be used to view LED spectrum.

measuring H
measuring H4

measuring H3

measuring h

measuring H2

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Charged Sheet

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Use “Fun Fly Stick” to charge up conductive sheet.

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Mylar strands align with electric field.

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Place support rods together to form cylinder. Electric field of cylinder points outward radially.

  • Located in L01, section A-2
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Homopolar Motor

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Wire balances on top of battery and is free to rotate. Top of wire touches positive terminal; bottom of wire touches magnet connected to negative terminal. Wire completes circuit and current travels through wire. Direction of magnetic field creates a Lorentz force that causes wire to turn.

Historical significance: First electric motor. First successful model devised by Michael Faraday. See: https://en.wikipedia.org/wiki/Homopolar_motor

  • Located in L01, section B-4.

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Sunset Egg

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Appearance of egg mimics that of the sky.

Glass egg is translucent, milky white, and contains no pigment- only microscopic particles that scatter light. Short wavelengths of light (blue) have a tendency to scatter off the microscopic particles in the glass; while long wavelengths of light (red and yellow) tend to pass through.  The egg therefore appears yellowish red when held in front of a light source, and blue when held in your hand.

  • Located in L01, section B-6
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Coulomb Force on Water

coulomb force on water1

coulomb force on water 2

Charge teflon rod with fake fur (shown in above photo) by rubbing together.

When charged rod is brought into the proximity of water stream, attraction between water and charged rod will cause stream to deflect.

  • Rod and fur located in L01, section A-1.
  • Bucket with hole, and tub, located in L35, section G-3.

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Temperature and Sound

Sound and Temperature Pipes

Copper pipes chime when hit (hang by loop and tap with hard object). Pipes are identical in size and composition, and are therefore identical in pitch.

To see how temperature affects pitch, dip one pipe in liquid nitrogen and cool for 1 minute. Tap both pipes to hear differences in pitch. Caution: DO NOT TOUCH COLD PIPE WITH BARE HANDS. USE CRYO GLOVES. 

Pipes located in L02, section C-1. Ask for assistance with LN2.

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Weight of Air

weight of air 2

Lid of plastic bottle, shown above, is a pump, and can be used to pump air into container.

Place empty bottle on sensitive digital scale and record scale reading. Then pump additional air into bottle and re-weigh.

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  • Bottle and pump located in L02, section B-5.
  • Scale in L35, section D-2.
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Einstein Illusion

 

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Is the mask in the above image concave or convex? Strangely, it appears convex (sticking out towards you) even when viewed from the concave side. Even more strange: the face appears to turn and follow you as you view it from different angles.

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Below is a profile view of the mask.

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Illusion works best when mask is illuminated from behind.

 

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Past Light Cone (to Big Bang)

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In a Big Bang universe, the shape of our past light cone is not strictly conical, but tear-drop shaped. The moment of now is located at the pinnacle of the drop, the moment of the Big-Bang is located at the very base.

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To understand why our past light cone has this shape, recall that the distance from a light cone’s surface to its time axis is the photon’s emission distance. All of the photons we see today- from the very early universe- were emitted from regions of space that were, at the time, very close to us. (Spatial expansion caused these regions to separate very rapidly.) So, photons emitted very early in the universe’s history, and photons emitted very recently have small emission distances.

The slope of the light cone represents the recessional velocity of light with respect to our region of space. The fattest part of the light cone corresponds to the moment in time when the photons we are currently seeing, from the Big Bang, first began to approach us.

The model shown above is actually the light cone for a linearly expanding universe (expansion at a constant rate- i.e., recessional velocities do not change with time). The most accurate model for spatial expansion- lambda cdm- is actually very close to this in shape.

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Size of Oil Molecule

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When droplet of olive oil (oleic acid) is placed on water, oil spreads out until oil layer is 1 molecule high.

If the oil “spill” radius and the size of the original droplet can be measured, one can estimate the length of the oil molecule.

Volume of original droplet = volume of oil spill pancake.

Use wire loop (diameter~1mm), to estimate volume of droplet (assume droplet is wafer, not sphere). Use calipers to measure.

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Dip loop in olive oil.

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Remove excess oil using paper towel.

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Dust surface of water with lycopodium powder. This allows you to see clearly the final diameter of the spill. The larger the container the better.

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Dip tip of wire loop into water. Oil immediately spreads out to form circle (very cool to watch!).

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Should get order-of-magnitude accuracy.

  • Lycopodium powder and oil located in L35, corrosive materials cabinet (powder is safe to handle).
  • Tub located in L35.
  • Calipers located in L35, section D-2.
  • Tape measure in L35, section A-1.
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Friction Pen

friction pen

Heat of friction causes ink in “Frixion” erasable pens to disappear.

Ink reappears when exposed to cold temperatures.

Use lighter for high temp. (Be careful not to burn paper. Just wave flame in front of paper until ink disappears)

Use liquid from compressed air to achieve cold temperatures. (Invert can and spray. Be careful not to get liquid on skin. Extremely cold.)

 

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friction pen 3
friction pen 5

friction pen 6

 

 

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Leydenfrost Propagation

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Heat aluminum blocks to 350 degrees C using adjustable hot plate shown in photo.

Use water dropper (with demo) to place droplets of water onto surface of hot aluminum blocks. Leydenfrost effect causes droplets to hover, and prevents them from evaporating immediately.

Droplets on the ridged block are propelled along the surface- from right to left in above photo.

Raise one edge of the hot plate slightly, so that droplets on smooth surface slide down while droplets on the ridged surface climb up.

See more about this here: http://www.wimp.com/when-water-flows-uphill-the-leidenfrost-effect/

 

 

 

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Static Friction Incline

static friction incline

 

  • Friction prevents the metal washer on incline from slipping. Washer will begin to slide down plane when angle is great enough (one can show that the coefficient of friction is equal to the tangent of the angle when the washer just begins to slip). Materials include: rubber, glass, wood, and teflon.
  • Use angle ruler (shown in photo) to measure angle.
  • Materials located in L02, section B3. Angle ruler in L45, with rulers.
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Olive Oil Fluorescence

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olive oil fluorescence

  • Olive oil fluoresces when illuminated by light within a certain frequency range. Violet light causes fluorescence, but attenuates quickly. Green light causes fluorescence but doesn’t attenuate. Red light scatters but does not fluoresce or attenuate.
  • Oil and lasers in L01, section B5 (or B6).
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Faster-than-g Falling Chain

falling-chain

  • Hold both ends of the chain- one end in each hand- so that the chain hangs freely and forms a U shape.
  • When one end of the chain is released it accelerates toward the ground faster than g. To prove it, drop an object simultaneously with the chain end, and listen to hear which one strikes the ground first.
  • Requires standing on ladder.
  • Chain located in L02, section B3. Plastic balls in section A2.
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Tonic Water Fluorescence

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Light, of high enough frequency, will cause quinine (found in tonic water) to fluoresce. The emitted light is a brilliant blue color. Also works with a black light.

Location:  Tonic water and violet laser pointer in L01, section B4. Black light in section A1 (or A2).

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Refraction with Water

smoke on the water 1

laser refraction 1

laser refraction 2

total internal reflection

  • Refracted beam of light made visible with water, coffee creamer, and smoke.
  • Fill container half way with water. Mix in 1 or 2 pinches of non-dairy coffee creamer.
  • Use smoke maker (blue device in top photo) to fill container with smoke. Place lid on container to contain smoke.
  • Use laser pointer to create beam of light.

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Impulse Block

impulse block 1

  • Two different balls can be rolled down incline to collide with wooden block. When rubber, bouncy ball collides with block, block tips over.
  • However, when non-bouncy ball collides with block (looks identical to bouncy ball) block does not tip over. Balls have same size and weight.

Location

  • Balls and block located in L02, section B5.
  • Track in Lo2, section B2.
  • Jacks in L35, section D1.
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Hammer Balance

hammer balance

hanging hammer 1

 

hanging hammer 2

  • Hammer balances in a manner that appears impossible, but does so because 1) center of mass is not beyond edge of table, and 2) angular displacement of hammer increases potential energy of system, meaning system is stable. Stick end can be pushed very close to table edge, as seen in above photo.
  • Demo located in L02, section B4
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Airfoil

air foil 2

 

air foil 1

 

airfoil

  • When air is blown across the surface of airfoil (paper wing), high pressure results on the lower side, and low pressure on the upper side, creating lift. What’s interesting, and non-intuitive, is that when the blown air is directed entirely over the top of the wing lift results, causing the wing to rise.
  • Located in Lo2, section D1 or D2. Air source in L35, B3 corner.

 

 

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Smoke Rings

smoke rings 1

 

smoke rings 2

  • Fill container with smoke using smoke maker (blue thing on right in above photo).
  • Tap the diaphragm on the bottom of the bucket to produce vortices of smoke. The gentler the tap the slower the ring velocity.
  • Use a black background for best visibility.
  • Located in L02, section D1 or D2
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Sound of g

sound of g 1

sound of g 3

sound of g 2

  • Nuts are tied to two separate ropes. Spacing between nuts on rope 1 is constant; spacing between nuts on rope 2 goes as the square of the distance from the end of the rope.
  • Hang ropes vertically and drop onto wooden platform. When rope 1 falls sound made by nuts (hitting board) increases in frequency, indicating acceleration of rope. When rope 2 falls, the nut-hitting-board sound is periodic, due to r^2 spacing.
  • Note: When hanging string, first nut (on bottom of string) rests upon board. So first nut does not fall- merely used as an a position anchor.
  • Located in L02, section B3.

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Light Bulb Energy Usage

 

 

light bulb energy usage

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  • When bulbs consume the same amount of power (same wattage) their brightness differs substantially- the incandescent bulb is much dimmer than both the compact fluorescent and the LED, which are of comparable brightness.
  • Bulb power can be adjusted using sliders. Meter connected to bulb tells both watts and volts.
  • Located in L01, section B5

 

 

 

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Inertia String Break

inertia break

inertia break2

  • Hang a 1 Kg mass by a piece of masking tape (just wrap the tape around the hook of the weight).  With the weight dangling, yank upwards on the tape. The tape will break if the yank is quick enough.
  • Instead of yanking, hoist weight upwards slowly and tape will not break.
  • Tape breaks much more easily than string, and is easier to hold on to.

Location

  • Masking tape located in L35, above the sink, on a peg.
  • Weight located in L02, section A1.

 

 

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Speed of Light in Water

Speed of Light in H2Ob

Speed of Light in H2O

  • Use speed of light set-up to measure velocity of light (pulsed laser, photo detector, oscilloscope). Two different light paths are required. Place a tank of water in one of the paths and observe the time delay that results. Velocity of light through water can be measured and compared to theory.
  • See lab lecturer for set up details.
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Shielding

Shielding

  • Use detector to measure radiation at various distances from radioactive source; instead of varying distance use thin sheets of aluminum and vary thickness of barrier.
  • Detector and sources located in radioactive materials storage room. Thin sheets of aluminum in L35.
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Poisson Spot

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  • Shine coherent light onto a spherical object and a dim spot of light appears in the center of the object’s circular shadow. This spot is called a Poisson spot, or Arago spot, and can be explained using the wave interpretation of light.
  • Green or red lasers, diverting lens, optics track and components located in L35, section A. BB in glass slides located in L01, section B6.
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1 over r^2 lights

1 over r-squared 2

1 over r-squared

  • Show, qualitatively, that light intensity falls off as 1 over the square of the distance.
  • Bulbs have equal luminosity. When covered with translucent domes smaller dome is noticeably brighter. Amount of light is equal, but larger surface area means lower light density, i.e. lower brightness.
  • Located in Lo1, section B6.
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Marble Bounce

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  • Glass has a very high coefficient of restitution. This makes glass marbles very bouncy, if dropped on very hard surfaces. When a marble is dropped onto the head of a hardened steel hammer (as shown on the left in the above photo) the marble bounces almost back up to the height of release. If dropped onto the surface of non-hardened steel (as shown on the right) the marble only bounces about 2/3 of the way back up.
  • Located in L02, section B4
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Chain Fountain

chain fountain

Few demos are as simple and surprising as this one.

  • Chain appears to levitate as it falls out of cup.
  • Elevate cup above floor 5 to 7 feet. Pull end of chain out of cup to begin initial descent. Chain will self-siphon.
  • While the chain falls at an accelerating rate, a standing wave develops above the lip of the cup and levitates.
  • See a brief youtube video here.
  • See a slow-mo video here, with a conceptual explanation.

Located in L02, section B-3.

 

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Induction Solenoids

Induction coils

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  • When current through a solenoid changes, a magnetic field is induced within the solenoid. If two solenoids are concentric with each other, the induced field in one solenoid produces a changing current in the other.
  • Connect a power supply to one solenoid and a galvanometer to the other.
  • Unless steel rod is inserted in innermost cylinder (shown above), induced magnetic field is too week to produce a noticeable effect. Steel rod greatly enhances effect.

Location

Solenoids: L01, section B-2

Galvanometer: L35, section F-3

Power supply: L35, section F-1

 

 

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Wimshurst Generator

Wimshurst Generator Demo Picture
Wimshurst Generator Demo Picture

  • Hand-cranked charge separator. Generate large sparks for
    entertainment or for use in various electrostatic experiments.
  • Use generator to charge capacitor plates or Leyden Jar.
  • Dip conductive pith ball in between parallel plate capacitor
    hooked to W-generator; crank W-generator; pith ball bounces back and forth
    between plates.
  • Located in L01; section A2, covered in plastic bag.
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Van de Graaff Generator

 

Van de Graaff Generator Demo Picture

  • Principle: Static electricity is cool.
  • Located in L01, section A2
  • Van de Graaf accessories are located beneath Van de Graaff
    generator in plastic containers.

Some ideas for experiments beyond the typical shock-myself-and-my-students:

  • Bend a paper clip into an L shape and tape it to the charged sphere to create
    an ion gun; point the paper clip at the palm of your hand to feel the “ion
    wind”. Point the paper clip at your shirt to charge your shirt up- after
    30 seconds shirt should begin sticking to your chest.
  • Place a cup of styrofoam peanuts, or a stack of styro or aluminum plates
    on top of the sphere, turn on generator and watch stuff fly.
  • Dim the room lights, touch one end of a fluorescent bulb to the charged
    sphere and the other end of the bulb to the small discharging sphere. Bulb
    will flicker.
  • Using a squirt gun shoot a stream of water past the charged sphere; water
    should ionize and stream will disperse.

Additional Van de Graaff demo ideas

 

 

 

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Hydrogen Fuel Cell

 

Hydrogen Fuel Cell Demo Picture
Hydrogen Fuel Cell Demo Picture

Located in L35, section H-3.

 

Very nice (and expensive) demo. Please handle with care.

For detailed operation instructions see Instructions booklets-
one for fuel cell stack, and one for electrolyzer.

  • Connect fuel cell stack to electrolyzer as shown in above picture.
  • Fill tall cylinder with distilled water up to the 0 cm mark.
  • Fill the water reservoir of the electrolyzer with deionized water up to the -A- mark.
  • Connect the power supply, or solar cell, to the positive and negative terminals of the electrolyzer. Current causes water to split into oxygen and hydrogen. The oxygen escapes into the atmosphere, and the hydrogen accumulates in the gas storage tank (tall cylinder).
  • When hydrogen gas is allowed to flow into the fuel cell stack (see fuel cell operating instructions booklet; pg 9), the voltage difference that develops across the stack can be used to power the fan (see above picture).
  • Also, the voltage difference across each individual cell can be measured with a volt meter.

For Demo and Lab ideas see “Fuel Cell Technology for Classroom
Instruction” booklet.

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Astro-Blaster

 

Astro-Blaster Demo Picture

  • Purpose: Illustrate principles of conservation of momentum
    and energy, specifically during the creation of a supernova.
  • Hold tip of AstroBlaster as shown; release when hanging straight
    down. Blasted capsule can reach heights of over 5 times the drop height.
  • May consider wearing protective goggles for this one.
  • Location: L02, section B5

 

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High/Low Road

 

High/Low Road Demo Picture

  • Purpose: Demonstrate properties of gravitational potential
    energy.
  • Balls start moving and end with identical velocities, but ball on longer track traverses path more quickly.
  • Prove that balls end with identical velocities by showing they fall the same distance from the end of the track. Use carbon paper to show location of impact. 
  • Located in L02, section B2