$A$ rubber ball is dropped from a height of $5 \, m$ on a planet where the acceleration due to gravity is not known. On bouncing,it rises to $1.8 \, m$. The ball loses its velocity on bouncing by a factor of

$A$ ball falls freely from rest from a height of $6.25 \ m$ onto a hard horizontal surface. If the ball reaches a height of $81 \ cm$ after the second bounce from the surface,the coefficient of restitution is

$A$ particle of mass $m$ moving with speed $2v$ collides with a mass $2m$ moving with speed $v$ in the same direction. After the collision,the first mass is stopped completely,while the second one splits into two particles each of mass $m$,which move at an angle of $45^o$ with respect to the original direction. The speed of each of the moving particles will be:

$A$ ball is dropped from a height $h$. If the coefficient of restitution is $e$,to what height will it rise after jumping twice from the ground?

$A$ ball moving with a velocity of $9 \ m/s$ collides with another similar stationary ball. After the collision,both balls move in directions making an angle of $30^{\circ}$ with the initial direction. After the collision,their speed will be $-$

$A$ ball is dropped from a height $h$ onto a ground level. If the coefficient of restitution is $e$,what is the height reached by the ball after the $n^{th}$ bounce?