Question

If 7.84 x 10^7 J of energy is released from a fusion reaction, what amount of mass in kilograms would be lost? Recall that c = 3 x 10^8 m/s.

A. 7.06 x 10^24

B. 8.71 x 10^-4

C. 8.71 x 10^-7

D. 8.71 x 10^-10

Answer 1

For this, we use the relativity equation by Albert Einstein which is expressed as:

E = mc²

where E is the energy, m is the mass and c is the speed of light.

7.84 x 10^7 J = m ( 3 x 10^8 m/s )²
m = 8.71 x 10^-10 kg

Therefore, the correct answer is option D.