Re: electric field potential problem

The information you have given is not complete. The electric force is a 
force between two electric charges, so that you need to know either the 
magnitudes of both charges, or the magnitude of one charge and the strength 
of the electric field due to the other one. The physical constant that you 
use, the permitivity of free space, is usually given as 8.85 x 10e-12 
farads/meter. I am not sure which system of units you are using in which it 
comes out as 8.85 x 10e-11. After you calculate the electric force, you can 
divide the result by the mass of the moving charged object to get the 
acceleration. Actually the simplest way to solve the problem (if you have 
all the information you need) is to calculate the charged object's change 
in potential energy as it moves from one point to another. That change will 
be equal to the kinetic energy that it has gained or lost. Then you 
multiply by 2, divide by the mass, and take the square-root. The result is 
the change in velocity that has occurred.