Basic Idea:

• Examine the behavior of positve and negative charges.

• 6

	What:	How Many:	Where:
	Small piece of foil on silk thread	1	non-Majors storeroom, shelf K3
	50 cm rod	1	non-Majors storeroom, shelf A3
	Pendulum clamp	1	non-Majors storeroom, shelf C2
	Large bench clamp	1	non-Majors storeroom, shelf C4
	Glass rod	1	non-Majors storeroom, shelf HH3
	Hard rubber rod	1	non-Majors storeroom, shelf K3
	Dead animal fur (the deader the better)	1 chunk	non-Majors storeroom, shelf K3
	Plastic bubble wrap (works better than silk and paper towels!!)	1	non-Majors storeroom, shelf K3
	Metal spheres on insulated base	2	non-Majors storeroom, shelf K2
The following components are for the instructors' demo:
	Electrostatic generator	1	Lecture/demo room (Valentine 205A)
	Long metal rod	1	non-Majors storeroom, shelf B4
	Pendulum clamp	1	non-Majors storeroom, shelf C2
	Large rod base	1	non-Majors storeroom, shelf C4
	Hollow metal sphere on insulated rod	1	non-Majors storeroom, shelf K2
	Pith ball (carbon coated styrofoam) on string	1	Should be inside the hollow sphere!
	12" Wire	1	104 Lab
	Spade lug &'gator clip (already attached to hollow sphere)	1 each (see note below)	Majors storeroom, shelf B2
The following item is shared:
	Oscilloscope (an old one)	1	Majors storeroom - Ask Jeff

Notes:

• Lab setup (photo details):
  • Note: This experiment may already be set up in the 104 lab (Bewkes 204). The only change is that 152 will not use the electroscopes, but they will use the metal spheres on an insulated base. Ask Jeff what's going on.
  • The hollow metal sphere will have a spade lug and roach clip attached during storage. These are used to connect the sphere to the electrostatic generator.



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• Insulated spheres setup:

  

• Keep the intensity low on the oscilliscope. If it's too high, the effect is not as noticeble.
• Remove the plastic scale from the front of the oscilliscope display.

Note: Use a 12" wire (one that doesn't touch the lab bench), heavy gauge wire to connect the hollow sphere and the generator; this will prevent the sphere from discharging prematurely.