Write an equation for the average energy loss per collision ΔE of a neutron that is involved in both head-on and glancing scattering collisions. Suppose that a neutron has a head-on elastic collision...

Write an equation for the average energy loss per collision ΔE of a neutron that is involved in both head-on and glancing scattering collisions.

Suppose that a neutron has a head-on elastic collision with a helium atom. If the initial energy of the neutron is 1 MeV, what is the nal energy of the neutron after the collision?