Problem: Two stationary point charges of 5.00nC and 2.00nC are separated by a distance of 50.0cm. An electron is released from rest at a point midway between the charges and moves along the line connecting them.
Part A: What is the electric potential energy of the electron when it is
a) At the midpoint?
b) 13.0cm from the 5.00nC charge?
If possible just a brief explanation how you got the solution?