A particle of mass m and velocity u1 makes a head-on collision with another particle of mass 2m at rest. if the coefficient of restitution is such to make the loss of total kinetic energy a maximum,what are the velocites v1 and v2 after the collision?

Question

anonymous · Answer

Maximum KE is lost when the coefficient of restitution is zero. The their relative velocity on separation is zero, they move together. Therefore, v1=v2. 
Then, apply conservation of linear momentum and you'll get your answer.