Electromagnetic Fields of a Rotating Shell of Charge

A spherical shell of radius a carries charge Q uniformly distributed over its surface. Give expressions for the electric field E and magnetic field B everywhere in space when the shell it rotating with angular velocity ω about an axis. Compare these fields with those reported by an observer in a frame that rotates with angular velocity ω ′ about the same axis. It suffices to consider the low-velocity case, where ωr c and ω′r c for any relevant radius r.