Object A strikes the stationary object B with a certain give speed u head-on in an elastic collision. The mass of A is fixed, you may only choose the mass of B appropriately for following cases. Then after the collision:

Options

A. for B to have the greatest speed, choose `m_(B)=m_(A)`
B. for B to have the greatest momentum, choose `m_(B) ltlt m_(A)`
C. for B to have the greatest speed, choose `m_(B)ltltm_(A)`
D. for B to have the greatest kinetic energy, choose `m_(B) = m_(A)`

Answer

C, D

Explanation

(D) is true option because `V_(A)=(m_(A)-m_(B))/(m_(A)+m_(B)) U_(A)`
`V_(B)=(2m_(A))/(m_(A)+m_(B)) U_(A)`