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 = −4.00×10−9 C placed at corner A and then at corner B. EPEA = EPEB = q1 = +1.50×10−9 C q2 = +4.00×10−9 C