1. The problem statement, all variables and given/known data Two Styrofoam balls with the same mass m = 7E-8 kg and the same positive charge q are suspended from the same point by insulating threads of length L = 0.92 m. The separation of the balls is d = 0.024 m. What is the charge q? I am unable to add a graphic at this time. But i understand this is a common electrophysics problem, i think the problem describes it pretty well. 2. Relevant equations F = (k*q1*q2)/r^2 3. The attempt at a solution One thing I will do first is find the value "h", the vertical distance between 1/2d and the ceiling (essentially completing the triangle) Well I wasn't exactly sure where to start, and that may be part of the problem, so here is the thought process, I hope you can follow. I know Fnet = 0 Fy = 0 Fx = 0 I know to get q i need to find F from each charge. (note: FTy represents the Tension Force from the string in the y direction.) So Fy = -mg + FTy = 0 so mg = FTy How do find FTy? I understand it is a component of FT. would it be FTy = FT x (h/L) ?? So Fy = -mg + FT x (h/L) and from this i could get FT???? is that correct? If this is correct, I can also find FTx. FTx = FT x (1/2d)/L And Fx should = (FT x (1/2d)/L) - (k*q1*q2)/d^2 Since Fx = 0 i can set the above equation to 0 and solve for q?? This is what I tried to do anyways, does this make sense? Any input is appreciated!