Physics Demonstrations at Cal Poly Pomona
Demo Index:
Pira Index:
Title:
Description:
The cotton is first attracted to a charged rod, takes on the same charge and repels and floats above the charged rod.
Equipment:
1. Clear plastic tube w / cotton (stored in base behind stopper)
2. Rubber glove
Procedure:
1. Remove the cotton from the base of the tube and pull a small piece of cotton loose and stretch it into a wispy strip.
2. Put on the glove and rub it over the length of plastic tube several times to charge the tube.
3. Place the cotton onto the tube and it will at first be attracted. Let it set for a bit to take on the same charge as the tube.
4. Give the tube a quick flick to separate the cotton and if it has gained enough charge it will jump away from the tube. You can ‘float’ the cotton in the air above the tube.
