- #1
ghostfolk
- 59
- 1
Homework Statement
Find the energy stored in a solid sphere by integrating ##\frac{\epsilon_0}{2} \int E^2d^3r## given that ##E=k\frac{r^2}{4 \epsilon_0}## for ##0<r\le R## and ##E=k\frac{R^4}{4r^2 \epsilon_0}## for ##r>R##
Homework Equations
##U=\frac{\epsilon_0}{2} \int E^2d^3r##
The Attempt at a Solution
I'm just looking for the correct set up
##U=\frac{\epsilon_0}{2} [\int_0^R (k\frac{r^2}{4 \epsilon_0})^2d^3r+\int_R^\infty (k\frac{R^4}{4r^2 \epsilon_0})d^3r]##.