Hiroshima "Little Boy" Atomic Bomb Physics Help I just wanted some feedback on a paper I just finished. Did I do everything correctly and does it make sense? It seems my data supports information I found online: "It contained 64 kg (140 lb) of uranium, of which less than a kilogram underwent nuclear fission, and of this mass only 0.6 g (0.021 oz) was transformed into a different type of energy (initially kinetic energy, then heat and light)." http://en.wikipedia.org/wiki/Little_Boy Hiroshima “Little Boy” Atomic Bomb Cameron Facts: 64 Kg of Uranium-235 used in bomb 6.3 x 10^13 Joules released (estimated) during explosion Equation: E = mc2 Energy Efficiency: 6.3 x 10^13 = m x (300,000,000)2 m = 7 x 10^-4 Only .1% of starting Uranium-235 is turned to energy thus, (7 x 10^-4) / (.001) = .7 Kg Conclusion: “Little Boy” contained 64 Kg of Uranium-235 but, only .7 Kg of the starting mass was involved in the explosion. Furthermore, no more than .1% of the .7 Kg is converted to energy during nuclear fission. As a result, 7 x 10^-4 Kg of Uranium-235 was changed into 6.3 x 10^13 Joules.