A parallel-plate capacitor is constructed from two 13cm X 13cm electrodes spaced 0.90mm apart. The capacitor plates are charged to ± 20nC , then disconnected from the battery.
Part A How much energy is stored in the capacitor? Express your answer using two significant figures.
Part B Insulating handles are used to pull the capacitor plates apart until the spacing is 2.1mm. Now how much energy is stored in the capacitor? Express your answer using two significant figures.