Many nuclear reactors use heavy water moderators in which elastic collisions occur between neutrons and deuterons of mass 2.0 u.
(a) What is the speed of a neutron, expressed as a fraction of its original speed, after a head-on, elastic collision with a deuteron that is initially at rest?
(b) What is its kinetic energy, expressed as a fraction of the initial value?
(c) How many successive collisions will reduce the speed of a neutron to 1/59,000 of its original value?