:A 10 MeV photon penetrates into 100 g mass. It has 9 MeV of initial kinetic energy, of which (1.6 + 1.4 +2) MeV was converted into bremsstrahlung and into 2 photons of 0.51 MeV annihilation radiation. All these photons escaped from the 100 g mass. Find a) The kerma. b) The absorbed dose.