Question

A hollow metal sphere has inner and outer radii of 20.0 cm and 30.0 cm, respectively. As shown in the figure, a solid metal sphere of radius 10.0 cm is located at the center of the hollow sphere. The electric field at a point P, a distance of 15.0 cm from the center, is found to be E1 = 1.42 104 N/C, directed radially inward. At point Q, a distance of 35.0 cm from the center, the electric field is found to be E2 = 1.32 104 N/C, directed radially outward. Determine the total charge on the surface of the inner sphere, the inner surface of the hollow sphere, and the outer surface of the hollow sphere.