(a)[2]
State the law of conservation of momentum.
(b(i))[3]
Calculate the combined initial momentum of the two balls.
(b(ii))[2]
Calculate the value of $v$.
(b(iii))[3]
Calculate the overall initial kinetic energy of the two balls.
(c)[1]
Explain how you would determine whether the collision is elastic.
(d)[2]
Use Newton’s third law to explain why, during the collision, the change in momentum of X is equal in size and opposite in direction to the change in momentum of Y.