Courses: P1, P4, P14, P16
These can be used for a number of electrostatic demos. Charge one and they attract. Allow them to touch and they then repel.
Setup: Use a needle and monofilament line to thread through a piece of aluminum. Tie a knot to prevent the line from slipping back through, and place a small piece of captan tape over it to aid in retention. Wrap the aluminum foil around a ball, remove the ball and reform the aluminum. The bottom can be left partially open. Hang two, a few inches apart, from a lab stand.
