1. The problem statement, all variables and given/known data A point charge q = -0.5nC is fixed at the origin. Where must a proton be placed in order for the electrical force acting on it to be exactly opposite its weight? 2. Relevant equations F= k(q1)(q2) ------------ r^2 3. The attempt at a solution Trying to solve for distance (r), but coming across a few problems; If the force acting on it is exactly opposite its weight, does this make F=0? should I be substituting 0 for F? Where would I substitute -0.5? in q1 or q2? And what would I place in the other? ???