1. The problem statement, all variables and given/known data Four point charges are placed at the corners of a square of side 1m as shown in Fig 18.54 Find a) the electric field, and b) the electric potential at the center of the square Photo is attached 2. Relevant equations coulomb's law Ans of a=76.3 x 10^3 NC^-1 upward Ans of b=-25.4x 10^3 V 3. The attempt at a solution I can do part a by 2x(2/10^6)x2x8.99x10^9xsin45 + 2x(2/10^6)x8.99x10^9xsin45=76.3 x 10^3 NC^-1 upward. I just attempted b part by 2x(2/10^6)xroot2x8.99x10^9xsin45 + 2x(1/10^6)xroot2x8.99x10^9xsin45 because V=ED I just multiply each term by its length 1/root2 from the center. But the answer seems to be one third of the answer from part a, please teach me how to do.