What is the magnitude of the force between the two charges?

[yo_man]

Homework Statement

Two positive point charges are 5.20 cm apart.
If the electric potential energy is 71.0 microJoules, what is the magnitude of the force between the two charges?

Homework Equations

potential energy = U = qV
E=kq1q2/r^2
F=qE

The Attempt at a Solution

I've tried manipulating the equations and it does not work. Also, I'm not sure if this has something to do with dipoles

 

[Kurdt]

The electric potential energy is given by:

$$U=\frac{kq_1q_2}{r}$$

Since both charges are the same you can work them out from the potential energy given and then solve for the force.