A heavy body moving with a velocity of $6\,ms^{-1}$ collides elastically with a light body (whose mass is half of mass of heavy body) at rest. The velocity of light body will be (in $ms^{-1}$ )

A ball hits the floor and rebounds after inelastic collision. In this case

Six identical balls are lined in a straight groove made on a horizontal frictionless surface as shown. Two similar balls each moving with a velocity $v$ collide elastically with the row of $6$ balls from left. What will happen

The quantity that is not conserved in an inelastic collision is

A body of mass $m$  moving with velocity $v$ collides head on with another body of mass $2m $ which is initially at rest. The ratio of K.E. of colliding body before and after collision will be

In the figure shown, the two identical balls of mass $M$ and radius $R$ each, are placed in contact with each other on the frictionless horizontal surface. The third ball of mass $M$ and radius $R/2$, is coming down vertically and has a velocity $= v_0$ when it simultaneously hits the two balls and itself comes to rest. Then, each of the two bigger balls will move after collision with a speed equal to