Chapter 6.3 - Applying Gauss's Law
Electric field outside of a spherical gaussian surface:
$$ \vec{E} = \frac{1}{4\pi \varepsilon_0} \frac{Q}{r^2} \hat{r} $$
Electric field inside of a spherical gaussian surface:
$$ \vec{E} = \frac{1}{4\pi \varepsilon_0} \frac{Q_{\text{enc}}}{r^2} \hat{r} $$