Four point charges with equal magnitude q are placed at the corners of a square, with a distance from each corner to the center of the square a. Two of the charges are positive, and one of the them in negative, as shown below. A fifth charge Q is then brought from far away to the center of the square.
(a) By how much does the potential energy of the system change when the charge Q is brought to the center of the squre? Your answer should be in terms of a,q,Q, and fundamentalconstants.
(b) After it is borught to the center of the square, what is the force (magnitude and direction) on the charge Q? Your answer should be in terms of a,q,Q, and fundamental constants.
