Subject: electric field potential problem

could u help me with this formula..
the formular for electric field potential i hope u know it... i am trying 
to get velocity from the formula eg. an object has mass 0.1g 
charge 10coulombs and the constant for permitivity of free space is 
8.85x10power-11 and the objects radius is 0.5m what is the velocity??

The electric potential formula only gives me force and i have already 
tried force=massxacceration and the using squareroot of 
r=radiusxacceleration to find velocity but it dosent work help

Re: electric field potential problem