Three 3.0 g balls are tied to 80-cm-long threads and hung from a single fixed point. Each of the balls is given the same charge q. At equilibrium, the three balls form an equilateral triangle in a horizontal plane with 20 cm sides.
F (of 1 on 2) = F (of 2 on 1)
The Attempt at a Solution
Since they all have the same charge, I figured that the forces would be equal at each point. All points are in the same plane, so I assumed they only have x and y components. I tried using F=kq1q2/r^2=kq2q3/r^2=kq1q3/r^2 but it ended up a huge mess with all the charges canceling. But they all have the same charge? So should I use F=k2q/r^2 and do something with that?