$A$ ball is dropped from some height and after the first collision with the ground,if it reaches $\frac{3}{4}$ of its original height,then the percentage loss of its energy is:

$A$ ball of mass $M$ falls from a height $h$ on a floor. If the coefficient of restitution is $e$,the height attained by the ball after two rebounds is

$A$ ball is dropped from a height of $5\,m$. The time after which the ball stops rebounding,if the coefficient of restitution between the ball and the ground is $e = 1/2$,is ............. $s$.

$A$ ball makes a head-on collision with another ball of twice its mass,which is initially at rest,with a velocity of $1.5 \ m/s$. If the coefficient of restitution is $0.6$,what will be their velocities after the collision?

$A$ glass ball collides with a smooth horizontal surface with a velocity $\vec{v} = a \hat{i} - b \hat{j}$. If the coefficient of restitution of the collision is $e$,find the velocity of the ball just after the collision. ($x$-axis is along the ground and $y$-axis is along the vertical).

$A$ mass $m$ moves with a velocity $v$ and collides inelastically with another identical mass at rest. After the collision,the $1^{st}$ mass moves with velocity $\frac{v}{\sqrt{3}}$ in a direction perpendicular to the initial direction of motion. Find the speed of the $2^{nd}$ mass after the collision.