Gauss's Law
A positive point charge q sits at the center of a hollow spherical shell. The shell, with radius R and negligible thickness, has net charge -2q. Find an expression for the electric field strength (a) inside the sphere, r < R, and (b) outside the sphere, r > R. In what direction does the electric field point in each case? (c) What is the numerical value of the electric field if the q = 26.0 nC, and R = 32.0 m.