Another Relativistic Mass Question (1 Viewer)

[TeaYarn]

A typical nuclear reaction which releases energy from uranium is:

235U92 + 1n0 -----> 148La57 + 85Br35 + 3(1n0)

where mass: 235U92 = 3.904 x10^-25 kg
1n0 = 1.676 x10^-27 kg
148La57 = 2.457 x10^-25 kg
85Br35 = 1.410 x10^-25 kg

a) Find the mass defect in this reaction
b) Find the energy released in the reaction

 

[Zeref]

A typical nuclear reaction which releases energy from uranium is:

235U92 + 1n0 -----> 148La57 + 85Br35 + 3(1n0)

where mass: 235U92 = 3.904 x10^-25 kg
1n0 = 1.676 x10^-27 kg
148La57 = 2.457 x10^-25 kg
85Br35 = 1.410 x10^-25 kg

a) Find the mass defect in this reaction
b) Find the energy released in the reaction

a. not sure what it means by defect.... maybe the difference in the mass between lhs and rhs?
b. use e=mc^2 for the rhs

 

[Amundies]

Zeref is correct, mass defect is calculated through the difference in mass between the LHS and the RHS. In this sort of reaction the RHS will have a smaller mass since some of the mass transforms into energy (which the nuclear power plant utilises for power).
Then to find the energy released, use e=mc^2 (where m = mass defect in kg and c = speed of light). The answer is in joules.