Point charges g1+2.00uc and g2-2.00uc are placed at adjacent corners of a square for which the length of each side is 4.50 cm. point a is at the center of the square, and point b is at the empty corner closest to 92. take the electric potential to be zero at a distance far from both charges. a) what is the electric potential at point a due to ql and q2? b) what is the electric potential at point b? c) a point charge q3 = -4.00 uc moves from point a to point b. c) how much work is done on q3 by the electric forces exerted by q1 and 92?