1 A neutron in a reactor makes an elastic head on collision with the nucleus of an atom initially at rest. Assume: The mass of the atomic nucleus is about 14.9 the mass of the neutron. What fraction of the neutron's kinetic energy is transferred to the atomic nucleus?
2 If the initial kinetic energy of the neutron is 4.09 · 10^-13 J, find its final kinetic energy. Answer in units of J.
