Deriving an equation

kevykevy

Two identical small charged spheres, each having a mass of m, hang in equilibrium as shown below. If the length of each spring is L and the angle 0 (theda), find the expression for the magnitude of the charge on each sphere, assuming the spheres have identical charges in terms of m, g, k, L, and 0.



I don't have a clue where to start, please help.

kevykevy

It's using Coulomb's Law and I understand the basis of the question and how to figure it out, but I don't know which equations are available to use.