How much mass of Uranium (235/92U) is required to produce the same amount of energy as burning 1.1 kg of coal (about 3.3×10 7 J )? Assume that 200 MeV is released per fission. Solution Here , let the number of fission is N Now, for total energy N * energy of each fission = total energy N * 200 *10^6 * 1.602 *10^-19 = 3.3 *10^7 N = 1.03 * 10^18 total mass of Uranium = (1.03 *10^18)*235/(6.022 *10^23) total mass of Uranium = 0.00402 gm the total mass of Uranium is 4.02 *10 -6 Kg .

1. How much mass of Uranium (235/92U) is required to produce the same amount of energy as
burning 1.1 kg of coal (about 3.3×10 7
J )? Assume that 200 MeV is released per fission.
m U = ?
Solution
Here ,
let the number of fission is N
Now, for total energy
N * energy of each fission = total energy
N * 200 *10^6 * 1.602 *10^-19 = 3.3 *10^7
N = 1.03 * 10^18
total mass of Uranium = (1.03 *10^18)*235/(6.022 *10^23)
total mass of Uranium = 0.00402 gm
the total mass of Uranium is 4.02 *10 -6 Kg