PIRA Code(s): 1D60.20 Set up time:5 minutes Operation: Mount apparatus to ring stand using clamp, adjust until apparatus is horizontal, cock the apparatus spring, and place the masses (one at the end of the apparatus and one on the bar that extends from the apparatus), release, and one ball will fall from rest (hung on the rod) while the other ball is struck by the rod and has an initial horizontal velocity. The balls should hit the table at the same time, which can be heard clearly by students. Repeat by cocking spring to different compression. Repeat by clamping apparatus at a different height to show that height has no effect on the simultaneity of the fall. Physics and Science Concepts: Projectile Motion Safety: Once spring is compressed, do not put hands in front of the end of the rod.
PIRA Code(s): 1M40.20 Set up time:none Operation: Place ball at the top of track and let it fall. To show students the minimum height required to loop the loop, place the ball on the track at a height that is about double the height of the loop. Physics and Science Concepts: Mechanics, Work and Energy, Conservation of Energy, Centripetal Force Safety: Do not stand where the ball exits the track.
PIRA Code(s): 3A10.20 Set up time:1 minute Operation: Move the weight along the hacksaw blade. Pull back on the blade and release. When the weight is at the top of the blade the frequency is smaller compared to when the weight is at the bottom. Physics and Science Concepts: Oscillations Safety: Edge of blade may be sharp.
PIRA Code(s): 4A30.20 Set up time:2 minutes Operation: Try putting the ring around the ball. At room temperature the ring is slightly larger than the ball. Heat the ball over a Bunsen burner and it will no longer fit through the ring. Physics and Science Concepts: Thermodynamics, Thermal Properties of Matter, Thermal Expansion Safety: Use caution when using a Bunsen burner. The Bunsen burner is not included in the experiment.
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): 5A22.22 Set up time:3 minutes Operation: First, show the electroscope in resting stage. Then, charge a rod or other material by rubbing the object in a cloth. Place this near the plate of the electroscope and observe the deflection of the needle. To keep the needle deflected, scrape the plate with the charged object. A decrease in deflection occurs when an oppositely charged object is placed near the plate. Physics and Science Concepts: Electrostatics Safety: None
PIRA Code(s): 5B30.20 Set up time:5 minutes Operation: Use the Van der Graaf or Wimshurst generator to charge the ovoid. Touch a proof plane to the pointed end of the ovoid and another to the spherical end. Place the proof planes on the electroscope plate. The deflection will be greater from the proof plane that touched the pointed end. Physics and Science Concepts: Electrostatics, Surface Charge Density Safety: Electroscope can be obtained from demonstration number 5A22.22.
PIRA Code(s): 5C10.20 Set up time:none Operation: Charge the plates using the Van de Graaff. Disconnect wire going from top of sphere to fixed plate at plate end. Change the spacing of a charged parallel plate capacitor while it is attached to an electroscope. Observe changes in electroscope pointer. Physics and Science Concepts: Capacitance Safety: Electroscope can be obtained from demo 5A22.22. The Van de Graaff can be obtained from demo 5A50.30.
PIRA Code(s): 5E40.20 Set up time:1 minute Operation: Pour sulfuric acid into the glass container. Wait 5 minutes for the reaction to take place between the dissimilar metals. Place the voltmeter on the overhead and display the voltage generated in the cell. Physics and Science Concepts: Electromotive Force and Current Safety: Be careful around acid. Gloves and goggles should be worn when handling acid.
PIRA Code(s): 5K10.20 Set up time:1 minute Operation: Hook the leads from the galvanometer to the induction coil. Place a magnet in front of the coil. Turn the crank and the needle on the galvanometer should move. The connection between the galvanometer and the loop changes polarity every half turn. Physics and Science Concepts: Electromagnetic Induction, Electricity and Magnetism Safety: Magnet is extremely strong so do not place metal objects near it.