1. The problem statement, all variables and given/known data Q18. A 20 F capacitor is charged to 200 V. Its stored energy is: C. 0.4 J 2. Relevant equations q = CV u = .5CV^2 3. The attempt at a solution I tried plugging in the numbers and got 1.6E6, which isn't even close to the answer. I really don't know where to go with this one. I even went and found an energy calculator online and it came up with the same answer I got. Is stored energy not the potential energy of the capacitor?