PIRA Code(s): 3B30.30 Set up time:10 minutes (5 minutes to pump the bell jar) Operation: Plug in the pump and attach the clear tube of the pump to the valve. Turn the switch on the power supply to ascertain that the alarm is working properly. Then, pump out the air inside the bell jar. It will take about 5 minutes to obtain a low enough air pressure so that the alarm will not sound. Turn the alarm on and slowly open the valve, allowing the air pressure in the bell jar to increase. The sound of the alarm will also gradually increase. Physics and Science Concepts: Sound waves Safety: A glass jar containing a vacuum can be extremely hazardous if broken.
PIRA Code(s): 5A20.20 Set up time:1 minute Operation: Charge the rod by rubbing it the through the cloth provide or on your shirt. Hold the rod near a pith ball. The two balls will repel each other. The PVC gives a positive charge and the acrylic rod gives negative charge. Physics and Science Concepts: Electrostatics, Coulomb’s Law Safety: None
PIRA Code(s): 5A50.30 Set up time:10 minutes Operation: Plug in the generator. Turn on the rocker switch and adjust speed using potentiometer on the base of the Van de Graaff.
Other suggested uses include combining this with other electrostatic demonstrations found under a 5A50 heading. Also, throwing packing peanuts or taping strips of paper to the Van de Graaff are popular demonstrations. Physics and Science Concepts: Static Electricity, Friction Safety: The rod works best on dry days with the blue wig. Care should be taken when operating. Do not approach the generator while it is running. Use the grounding rod to discharge.
PIRA Code(s): 5F20.50 Set up time:5 minutes Operation: First, attach the metal rods to the battery by unscrewing the black caps and place the rods around the screws. Then replace the caps. Next, clip one light bulb on the metal rods to show a circuit with a single light bulb. To show series circuits, clip two bulbs together and place the end of each clip on opposite rods. To show parallel circuits, clip each bulb separately to the rods. The bulbs in series will glow less brightly than the bulbs in parallel. Physics and Science Concepts: Parallel and series circuits Safety: The ends of the rods pose an eye hazard.
PIRA Code(s): 5G50.50 Set up time:2 minutes Operation: A superconductor disc is placed in a styrofoam dish and liquid nitrogen is added to the dish. A small magnet is placed on top and within a few seconds it begins to levitate. Physics and Science Concepts: Superconductivity, Magnetic Materials Safety: Liquid Nitrogen can be obtained from the machine shop.
PIRA Code(s): 5H10.30 Set up time:3 minutes Operation: Place the magnet under the piece of paper and on the overhead. Sprinkle iron filings over the magnet and the filings should align with the magnetic field. Physics and Science Concepts: Magnetic Fields and Forces Safety: An overhead can be obtained from demonstration 9A36.10.
PIRA Code(s): 5K20.30 Set up time:2 minutes Operation: Set up the apparatus so that the silver pole sticks above the platform a few inches. Place a full ring around the tube and turn the apparatus on. This will make the ring jump into the air. Turn off the machine then, place the split ring around the pole, turn on the machine and this will not do anything. Resistive heating can be demonstrated by holding the full rings down and feeling them heat up. Next, turn off the machine, place the copper coil around the pole and press down on the copper rod sticking off the coil to create sparks. Also, place the light bulb circuit ring against the flat top part of the pole and watch it light up. Physics and Science Concepts: Lenz law, Electromagnetic Induction, Eddy Currents Safety: Do not place apparatus directly under a light. Do not stand above machine when the rings jump. Do not hold the full ring down too long, you may get burned.
PIRA Code(s): 5L20.14 Set up time:1 minute Operation: Plug in the circuit. Flip the switch that says line and then put the lever to the automatic side for the whole lamp to light up. Flip the line switch again and move the lever to the middle. Put the line switch on again and move the lever to the manual side. This will heat up the filament. Then move the lever a little away from the manual side for the entire light to be lit. Physics and Science Concepts: AC Circuits Safety: None