$A$ 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:

Particle $A$ moving with a velocity $v = 10 \ m/s$ experiences a head-on collision with a stationary particle $B$ of the same mass. As a result of the collision,the kinetic energy of the system decreases by $1 \%$. The speed of particle $A$ after the collision is: (in $m/s$)

$A$ sphere of mass $m$ moving with velocity $u$ collides with another sphere of the same mass $m$ at rest. If the coefficient of restitution is $e = \frac{1}{2}$, what is the ratio of their velocities after the collision?

$A$ 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?

$A$ lead ball of mass $2 \ kg$ moving with a velocity of $1.5 \ ms^{-1}$ collides with a ball of mass $3 \ kg$ at rest. After the collision,the second ball moves with a velocity of $1 \ ms^{-1}$ in the original direction of motion of the first ball. Find $\Delta KE$ in $J$.

$A$ 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