Electric force of Van de Graaff generator problem.

[geonerd]

A Van de Graaff generator is charged so that a proton at its surface accelerates radially outward at 1.45 10^12 m/s2.

Find the following.
(a) the magnitude of the electric force on the proton at that instant magnitude

(b) the magnitude and direction of the electric field at the surface of the generator


I am major stumped... Thanks for helping!

 

[Ush]

I'm not too sure about Van de Graaff generators but isn't this a simple F=ma=qE question?