hi, i'm completely stuck on this problem 1. The problem statement, all variables and given/known data the problem asks for an expression for the work required to create a square charge configuration starting with the charges starting at infinity: each side is length a. on the top left corner the charge is +q, top right: -q, bottom left: -q, bottom right +q 2. Relevant equations change in potential energy= work U= kqq/r 3. The attempt at a solution Since the charges begin at infinity, the work will equal the final potential energy. I think potential energies can be added, but if you add all the charges at equal distances you will get zero. I also tried chosing a corner and adding the potential energies relative to the corners but did not get the right answer. thank you for your help!