Video Problem #1, Lecture #14: An “X” particle (with energy 200 MeV) collides with its anti-particle (initially at rest), producing a pion and a photon. The X particle and its antiparticle both have a mass of 80 MeV/c², and the pion has a mass of 140 MeV/c². What are the energies of the pion and photon produced by this collision?