(a) Show that the electric field inside a sphere with uniform charge density pis given by E=", where r is the vector pointing from the center of the sphere to the 380 observation point. (b) Two spheres, each of radius R and carrying uniform charge densities +p and -p, respectively, are placed so that they partially overlap as shown in the figure below. The vector pointing from the positive center to the negative center is d. Show that the field in the region of overlap is constant and find its value. (Hint: The principle of superposition together with the result of (a) may be useful here.)