# Calculating the Kinetic Energy of a Point Charge From Far Away

1. Feb 13, 2008

### brandif22

1. The problem statement, all variables and given/known data
Four point charges form a square with sides of lenght d. Use k as the constant instead of 1/4*pi*epsilon not.

+q_______-3q

+2q______+5q

What would be the kinetic energy for 2q at a very large distance from the other charges? Express answer in terms of q, d, and appropriate constants.

2. Relevant equations
U=kqq/r , K=1/2mv^2

3. The attempt at a solution
I'm assuming that since the charge is a large distance away, there would be no kinetic energy acting on the charge 2q since it is far away from the forces of the other 3 charges.