Two ping-pong balls are painted with conductive paint. One ping-pong ball is mounted on an insulating stick; the other is hung on a string from the ceiling. The two balls are brought together such that they are barely touching (consider the initial tension to be purely vertical). Upon introducing a charged object to a ping-pong ball, charge is equally distributed to both of the balls. The hanging ball swings out from the mounted ball and eventually comes to rest. Your task is to determine the magnitude of charge on the balls given the following measurements: -A ping-pong ball has a diameter of 40mm -The hanging ball is hung from the ceiling with a 147.3cm long string. Note: this measurement is to the top of the ping-pong ball, not to the ball's center. -After charging, the two ping-pong balls have a center-center displacement of 6.40cm.