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 14.4 the mass of the neutron.
What fraction of the neutron's kinetic en-
ergy is transferred to the atomic nucleus?

2.) If the initial kinetic energy of the neutron is 6.83x10^-13J, find its final kinetic energy.
Answer in units of J