Concepts

Electrostatic induction, attraction of opposite charges

Overview

A 2" × 2" beam is placed on top of a low-friction watch glass. A PVC pipe is charged by rubbing fur on it (the pipe becomes negatively charged). The pipe is then held alongside one end of the 2 × 2 such that the board slowly rotates and moves toward the rod.

Details

Equipment

• [1] 2" × 2" beam with watch glass
  
• [1] PVC pipe
• [1] Rabbit's fur
  
• [1] Modelling clay (Play-Doh)

Classroom Assembly

1. Balance the 2 × 2 beam on top of a watch glass. Add modelling clay on either end of the beam to balance it properly.

Important Notes

• Make sure you hear the build up of charge on the rod. This will be indicated by a crackling noise during charging.
• As with most electrostatic demonstrations, this works best under 50% humidity.

Script

1. Rub the fur on the PVC rod.
2. Hold the near one end of the board. Observe the board moves slowly toward the rod.

Additional Resources