Qualitative/Quantitative Translation, 8 points About 21 minutes · 8 points
A solid sphere of radius R is made of an insulating material and carries a total charge +Q spread uniformly through its volume. Point P is inside the sphere, a distance R/2 from its center. Point S is on the sphere's surface.
(A) Predict whether the magnitude of the electric field at P is greater than, equal to, or less than half the magnitude of the electric field at S. In a clear, coherent, paragraph-length response that may also contain equations, justify your prediction using Gauss's law. Do not derive a general expression for the field in this part. 4 points
(B) Derive an expression for the magnitude E of the electric field at a distance r from the center of the sphere, for r < R, in terms of Q, R, r and physical constants, as appropriate. Begin your derivation by writing Gauss's law. 3 points
(C) Explain whether your expression in part B is consistent with your prediction in part A. 1 point
Ask Mia to mark it