$A$ body falling from a height of $10\,m$ rebounds from a hard floor. If it loses $20\%$ of its energy in the impact,then the coefficient of restitution is:

$A$ ball is moving with speed $20 \, m/s$ collides with a smooth surface as shown in the figure. The magnitude of the change in velocity of the ball will be ........... $m/s$.

$A$ particle falls from a height $h$ upon a fixed horizontal plane and rebounds. If $e$ is the coefficient of restitution,the total distance travelled before rebounding has stopped is

$A$ bullet of mass $10 \,g$ moving with a speed of $20 \,m/s$ hits an ice block of mass $990 \,g$ kept on a frictionless floor and gets stuck in it. How much ice will melt if $50 \%$ of the lost kinetic energy $(KE)$ goes to the ice? (Initial temperature of the ice block and bullet $= 0^{\circ}C$,Latent heat of fusion of ice $L = 80 \,cal/g = 336 \,J/g$)

$A$ ball with a coefficient of restitution $e = 0.5$ is dropped from a certain height. What is the percentage loss in kinetic energy after each bounce?

Two solid rubber balls $A$ and $B$ having masses $200 \, g$ and $400 \, g$ respectively are moving in opposite directions. The velocity of $A$ is $0.3 \, m/s$. After the collision,both balls come to rest. Determine the velocity of $B$ in $m/s$.