Suppose that a nuclear fission power plant and a coal-fired power plant both operate at 40% efficiency. Determine the ratio of the mass of coal that must be burned in 1 day of operating a 1000 -MW plant compared to the mass of ²³⁵U that must undergo fission in the same plant. The energy released by burning coal is 3.3×10⁷J/kg . The energy released per ²³⁵U fission is 200 MeV.