Okay this is more a physical motivated problem, but since its basically mathematics I'll ask here :
Given a vector field v(x)=C* x/|x| in $\mathbb{R}^3$. Calculate:
a) the surface Integral $\int\limits_{\partial K_{0}}\! v \, \mathrm{d}f$ for the surface $\partial K_{0}$ of a sphere with radius a around zero using Gauß theorem.
b) the integral $\int\limits_{\partial K_{b}}\! v \, \mathrm{d}f$ for the surface $\partial K_{b}$ of a spherealso with radius a which is moved the distance b away from zero along the $x$-Axis.(Again using Gauß theorem)
(Additionally: How to calculate the b) without Gauß to prove?)