A solid conducting sphere \(60 \mathrm{~mm}\) in radius carries a charge of \(5.0 \mathrm{nC}\). A thick conducting spherical shell of inner radius \(100 \mathrm{~mm}\) and outer radius \(120 \mathrm{~mm}\) carries a charge of \(-4.0 \mathrm{nC}\) and is concentric with the sphere.

(a) Draw the electric field lines for the situation, marking the location of all charge on your diagram.

(b) Calculate the surface charge density on the surface of the solid sphere and on the inner and outer surfaces of the thick shell.

(c) Determine the electric field as a function of \(r\), the radial distance from the center of the sphere.