Min tapes a piece of string to each of two ping-pong balls. He hangs the balls so that they are close to one another but do not touch. Later, he finds that they have pulled together. They are now touching. What could explain why two balls are now touching?
Athey have both lost their charges
Bthey have gained opposite charges
Cthey have both gained a positive charge
Dthey have both gained a negative charge
Athey have both lost their charges
Bthey have gained opposite charges
Cthey have both gained a positive charge
Dthey have both gained a negative charge