A hollow cylindrical shell of length L and radius R has charge Q uniformly distributed along its length. What is the electric potential at the center of the cylinder?
I use eta = Q/A = Q/2piRL
dq = (eta)*dA = Q/(2piRL)*2piRdL
dV = 1 / 4 pi epsilon 0 * dq/r where r = sqrt(L^2+R^2)
V...