A deuterium nucleus at rest absorbs a Gamma ray photon of energy 2.21 MeV and splits into a proton and a neutron. The neutron was found to be at rest after the disintegration. Calculate the mass of proton if it is known that mass of deuterium and hydrogen atom is 2.014740u and 1.008145u respectively. `[1 u=931 MeV//c^(2)]`
