The drawing shows a square, each side of which has a length of L = 0.250 m. Two different positive charges q1 and q2 are fixed at the corners of the square. Find the electric potential energy of a third charge q3 = -7.00 x 10-9 C placed at corner A and then at corner B.

Answer 1

figure the Va, then Vb from the original two charges.

PE at corner A= Va*q3
PE at corner B=Vb*q3