$A$ ball of mass $10\, kg$ is moving with a velocity of $10\, m/s$. It strikes another ball of mass $5\, kg$ which is moving in the same direction with a velocity of $4\, m/s$. If the collision is elastic,their velocities after the collision will be,respectively

$A$ ball of mass $m$ moving with a speed $u$ undergoes a head-on elastic collision with a ball of mass $nm$ initially at rest. The fraction of the incident energy transferred to the heavier ball is

In a carrom-board game,the striker and the coins are identical and of mass $m$. In a particular hit,the coin is hit when it is placed close to the edge of the board as shown in the figure,such that the coin travels parallel to the edge after the collision. If the striker is moving with speed $v$ before the strike,then the net impulse on the striker during the collision,if it moves perpendicular to the edge after the collision,is (assume all collisions to be perfectly elastic):

$A$ body of mass $m$ moving with velocity $v$ collides with a stationary body of mass $2m$. The fraction of kinetic energy lost by the body of mass $m$ is:

Assertion $(A)$: In an elastic collision between two bodies,the relative speed of the bodies after collision is equal to the relative speed before the collision.
Reason $(R)$: In an elastic collision,the linear momentum of the system is conserved.

$A$ particle of mass $m$,moving with a velocity $v$,makes an elastic collision in one dimension with a stationary particle of mass $m$. During the collision,they remain in contact with each other for an extremely small time $T$. Their force of contact with time is shown in the figure. Then $F_0 =$