# Homework Help: Studying Help Electric charges

1. Apr 6, 2005

### XxXDanTheManXxX

A barium nucleus has a charge of q = +56e (where e is the proton charge).
a. find the potential V at a radius of 10-12 m from the Nucleus. If a Proton is released from this point, how fast will it be moving when it is 1 m from the nucleus? Note: Assume V (infinity=0)
Any help?

2. Apr 7, 2005

### Davorak

I suggested in some of you other threads gaussian pill box. Learn to use it and love it. As an undergrad it looks like you have 1 or two more semsters of E&M and it wont go away. It might chagne a little though
$$\nabla \vec{E} = \frac{\rho}{\epsilon_0}$$