PURPOSE: To demonstrate electrostatic forces.

DESCRIPTION: Charge the glass cylinder positive by rubbing with silk or a plastic bag. Now roll a pop can or a paper towel roll across the table. You can also charge a rubber rod with fur and get the can to roll and atrack.

SUGGESTIONS: This demo works good in the winter when the air is dry. At other times of the year you may have trouble getting good results. See the demo crew for help.

EQUIPMENT: Glass tubes or rods, hard rubber rod, silk, fur.

SETUP TIME: 15 min.