Question

Find the mass energy of a particle of mass 1 u in joule and electronvolt.

Answer 1

Data : m = 1 u = 1.66 × 10^-27 kg, c = 3 × 10⁸ m/s,

1 eV = 1.602 × 10^-19 J

The mass energy,

[Note : The answer differs from the accepted value of about 931.5 MeV because of the rounding off errors in the data used.]