A classical view of the electron pictures it as a purely electric entity, whose Einstein rest mass energy,E = mc^2 is the energy stored in its electric field.
If the electron were a sphere with charge distributed uniformly over its surface, what radius would it have in order to satisfy this condition? Note: Your answer for the electron's "size" isn't consistent with modern quantum mechanics or with experiments that suggest the electron is a true point particle.
E = mc^2
F = qE
F = ma
E_sphere = Q/ (2*pi*r*epsilon_0);
U = 1/2CV^2
U = qV
I am not sure what to equate with E = mc^2 ?