posted by Randy .
Object A, which has mass m and a velocity Voi,collides with the Object B,which has mass 2m and a velocity 1/2Voj.Following the collision ,object B has a velocity of 1/4Voi.(a) Determine the velocity of object A after the collision.(b) Is the collision elastic? If not, express the change in the kinetic energy in terms of m and Vo.
Have you tried to start with the conservation of momentum?
Now, check the KE before the reaction, and the KE after the collision, and see if they are equal.