A neutron collides elastically with a helium nucleus(at restinitially) whose mass is four times that of the neutron. The heliumnucleus is observed to rebound at an angleθ2=40ofrom the neutron's initialdirection. The neutron's initial speed is 7.0 x 105m/s.
a) Determine the angle at which the neutron rebounds,θ1 measured from its initial direction.
b) What is the speed of the neutron after the collision?
c) What is the speed of the helium nucleus after the collision?