In a fission reaction of U-235, there was a release of 9.20 x 10^119.20x101111 kJ of energy. What amount of mass in kilograms would have been lost?

1 Answer
anor277
Sep 14, 2016

1.02xx10^-2*kg1.02×10−2⋅kg

Explanation:

We use the famous mass energy equivalence formula, E=mc^2E=mc2.

There were 9.20xx10^11*kJ9.20×1011⋅kJ evolved in the fission of ""^235U235U.

Thus E=9.20xx10^11*kJ="mass"xx(3.00xx10^8m*s^-1)^2E=9.20×1011⋅kJ=mass×(3.00×108m⋅s−1)2

And "mass"mass == (9.20xx10^11*kJ)/(3.00xx10^8m*s^-1)^29.20×1011⋅kJ(3.00×108m⋅s−1)2

But 1J1J == 1*kg*m^2*s^-21⋅kg⋅m2⋅s−2

"mass"mass == (9.20xx10^14*kg*cancel(m^2*s^-2))/((3.00xx10^8)^2*cancel(m^2*s^-2))

Thus a mass of 1.02xx10^-2*kg would have been converted.

Please review my figures. You might get a more nuanced answer in the Physics section.

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