A camera flash capacitor of 200 microfarads is charged to a potential difference of 100 V. Using U_E = (1/2) C V^2, how much energy does the capacitor store?

1. U_E = (1/2) C V^2 = (1/2)(200 x 10^-6 F)(100 V)^2. 2. (100 V)^2 = 1.0 x 10^4 V^2, so U_E = (1/2)(200 x 10^-6 F)(1.0 x 10^4 V^2) = 1.0 J. 3. This is enough energy to lift a 1 kg ball about 1 m off the ground, released in a flash lasting about a thousandth of a second. _Source: OpenStax Physics (CC BY 4.0), Ch 18 "Static Electricity", section 18.5 Capacitors and Dielectrics_