A particle of rest mass m disintegrates at rest into a particle of rest mass m, a particle of rest mass m, and a high energy photon (a y-ray). Find the maximum possible energy of the y-ray in the rest frame of the initial particle of rest mass m. energyy (b)mc2 2 (d) mc2 4 (a) 0 (c) 2mc2 a ths l1