A nonconducting, solid sphere of radius a is placed at the center of a spherical conducting shell of inner radius b (> a) and outer radius c, as shown in the figure below. A charge +Q is distributed uniformly through the sphere, which thus carries a charge density ρ (C/m3). The outer shell carries a total charge -3Q.
Find the electric field E(r) within the solid sphere, i.e., at a radius r < a
The Attempt at a Solution
I thought I knew what i was doing, but now i'm not quite so sure. I know what i have above is not the correct answer.