5. We re-revisit the spinning hollow sphere from homeworks 6 and 7 - a hollow insulating sphere of radius R and mass M centered at the origin is covered with a uniform surface charge σ = Q/(4πR²), rotating about the z-axis with angular frequency w. This time we consider both the magnetic field and the electric field produced by the sphere itself. T I 1 a. Calculate the total energy of the electric and magnetic fields. You can use the results from homework 7 for the B-field - you do not need to re-derive it. Be sure to include the magnetic field inside the sphere as well as outside. b. Calculate the total angular momentum of the electromagnetic fields. c. Find the relation between M and Q that would result in equal the mechanical and electromagnetic contributions to the angular momentum.