# Physics

posted by
**Rachel**
.

Picture the following:

A square with 4 point charges. Charges Q are diagonal from eachother, and charges -Q are diagonal from eachother. The length of each side is "a".

One of the -Q charges is "kicked" away with an outward initial speed of V0, while the three other charges are held at rest. If the moving charge has a mass m, what is its speed when it is infinitely far from the other charges?

Express the answer in terms of Q, m, V0, a and appropriate constants.