1. The problem statement, all variables and given/known data Four point charges, q, are fixed to the four corners of a square that is 13.1 cm on a side. An electron is suspended above a point at which its weight is balanced by the electrostatic force due to the four point charges, at a distance of 20 nm above the center of the square. (The square is horizontally flat, and the electron is suspended 20 nm vertically above the center of the square.) What is the magnitude of each fixed charge in coulombs? ___ C What is the magnitude of each fixed charge as a multiple of the electron's charge? ___ e 2. Relevant equations F = (k*q1*q2)/d^2 3. The attempt at a solution Since there is a net force of 0 for the electron, I assume that all q-charges are positive since they pull with equal force from all four directions. Since this is a 3-dimensional problem I use vectors when I calculate the forces on e(Fnet(x) = 0 , Fnet(y) = 0). When I try to break the forces on e up into vectors the angle that I get is 90 degrees. This somewhat makes sense since the distance of 20 nm is so small it can almost be negligible. I am not sure though, where to go from here.