1. The problem statement, all variables and given/known data A charge Q is fixed at each of two opposite corners of a square, while a charge q is fixed at the other two corners. (a) if the resultant electrical force on Q is zero, how are Q and q related? (b) could q be choosen to make the resultant electrical force on every charge zero? explain. F1 = force between Q's F2 = force between one Q and q's a = side of the square 2. Relevant equations F = (1/(4*pi*E))(q1*q2/r^2) 3. The attempt at a solution (a) F1 = (1/(4*pi*E))(Q^2/2a^2) F2 = (1/(4*pi*E))((Qq*sqrt(2))/(a^2)) I set them equal to each other and got: Q = -2q*sqrt(2) The answers weren't in the back of the book, so I'm not sure if that's correct or not The part I'm having trouble with is part (b). I don't think there can be a value for q that would make the forces on all the charges zero, but I don't know how to explain that. Thanks!