## College Physics (4th Edition)

We can write an expression for the energy stored in the capacitor when the separation distance is $d$: $E_1 = \frac{Q^2}{2C}$ $E_1 = \frac{Q^2}{2~(\epsilon_0~A/d)}$ $E_1 = \frac{Q^2~d}{2~\epsilon_0~A}$ We can write an expression for the energy stored in the capacitor when the separation distance is $1.5~d$: $E_2 = \frac{Q^2}{2C}$ $E_2 = \frac{Q^2}{2~(\epsilon_0~A/1.5d)}$ $E_2 = \frac{Q^2~(1.5~d)}{2~\epsilon_0~A}$ $E_2 = 1.5\times \frac{Q^2~d}{2~\epsilon_0~A}$ $E_2 = 1.5\times E_1$ The energy stored in the capacitor increases by 50%