If the average household uses electrical energy daily at the rate of 500. W, how much U-235 must undergo fission to supply this need for a year? (assume 200. MeV of energy are generated per fission and that the power plant is 46% efficient).

1. Energy used in Joules per year?

2. Fissions needed per year to produce the energy?

3. Mass of uranium needed to produce the fissions?