Answer
a. 1.022 MeV
b. 1876.6 MeV
Work Step by Step
The initial kinetic energy is approximately 0. Therefore, the total energy released is the rest mass energy of the pair of particles.
a. $E_t=2mc^2=2(0.511MeV)=1.022MeV$
b. $E_t=2mc^2=2(938.3MeV)=1876.6MeV$