$A$ ball is dropped from a height $h$. As it bounces off the floor,its speed is $80$ percent of what it was just before it hit the floor. The ball will then rise to a height of most nearly .............. $h$.

$A$ ball falls from a height $h$ upon a fixed horizontal floor. The coefficient of restitution for the collision between the ball and the floor is $e$. The total distance covered by the ball before coming to rest is [neglect the air resistance].

$A$ body moving along a straight line collides with another body of the same mass moving in the same direction with half of the velocity of the first body. If the coefficient of restitution between the two bodies is $0.5$,then the ratio of the velocities of the two bodies after collision is (treat the collision as one dimensional).

$A$ ball is allowed to fall freely from a height of $42 \ m$ from the ground. If the coefficient of restitution between the ball and the ground is $0.4$,then the total distance travelled by the ball before it comes to rest is (in $m$)

The quantity that is not conserved in an inelastic collision is

Hail stones are observed to strike the surface of a frozen lake at $30^{\circ}$ with the vertical and rebound at $60^{\circ}$ with the vertical. Assuming the contact to be smooth,the coefficient of restitution is