A 10.0 MeV photon is absorbed by a particle of mass of 20.0 MeV. The reaction is+xx. (a.) What is the mass (rest energy) of

A 10.0 MeV photon is absorbed by a particle of mass of 20.0 MeV. The reaction isγ+x→x.

(a.) What is the mass (rest energy) of the particle after the collision in MeV? 

(b.) Show numerically that the gain in rest energy is equal to the photon’s energy minus the particle’s kinetic energy after the collision.