QUESTION 3 An electron e with kinetic energy 0 45 MeV makes a head-on collision with a positron er that is at rest (A positron is an antimatter particle that has the same mass as an electron, but opposite charge ) In the collision the two particles annihilate each other and are replaced by two photons y of equal energy The reaction can be written as e tet - 2y a) Determine the speed of the electron just before it collided with the positron b) What is the momentum of the electron? ") What is the total energy of the electron? d) What is the total energy of the positron? e) What is the energy of each photon? f) What is the momentum each photon? (2 ) g) What is the speed of each photon? Give a reason for your