1. The problem statement, all variables and given/known data A point charge q = -0.80 nC is fixed at the origin. Where must a proton be placed in order for the electric force acting on the proton to be exactly opposite to its weight? (Let the y axis be vertical and the x axis be horizontal.) 2. Relevant equations F=(kq1 q2)/r^2 3. The attempt at a solution I first tried drawing this out and it seems like it should be a pretty straightforward problem, but I seem to be having more trouble with it than I probably should. I know that F would have to equal zero, but if I do that then I can't solve for r.