Question

In a nuclear reaction the mass defect is 2.0 x 10-6 g. Calculate the energy released, given that the velocity of light is 3.0 x 108 m/s.

Answer

Mass Defect, m = 2.0 x 10-6 g = 2.0 x 10-9 kg

Velocity of light, c = 3.0 x 108 m/s

Energy released, E = mc2

E = mc2 = 2.0 x 10-9 x (3.0 x 108)2 = 2.0 x 10-9 x 9.0 x 1016 = 1.8 x 108 Joules