A body of mass m moving with velocity u collides head on elastically with another body of mass 2m at rest. What is the ratio of kinetic energy of the colliding body before and after collision ?

A body of mass m moving with velocity u collides head on elastically w

1.	A body of mass m moving with velocity u collides head on elastically with another body of mass 2m at rest. What is the ratio of kinetic energy of the colliding body before and after collision ?
Answer» ANSWER :`9:1`