Electric Potential- Two Charges

[chapmanv]

Homework Statement

Two identical particles, each with a mass of 2.0 mg and a charge of 25 nC, are releasedsimultaneously from rest when the two are 4.0 cm apart. What is the speed of either particle at the instant when the two are separated by 10 cm?

Homework Equations

PE=ke*q1q2/r

The Attempt at a Solution

I have calculated the PE at 1.40e-4 V, but don't know where to go from there.

 

[BvU]

Hi chap, and welcome to PF :)

What's the PE by the time they are 10 cm apart ?