The friction coefficient between the horizontal surface and each of the block shown in figure is $0.2.$ The collision between the blocks is perfectly elastic. What is the separation between the blocks when they come to rest :- .............. $\mathrm{cm}$
$5 $
$10 $
$16$
$20$
When two particles collide elastically, then impulsive force can't change
In an elastic collision of two billiard balls which of the following quantities is not conserved during the short time of collision
A ball of mass $ m$ moving with velocity $V$, makes a head on elastic collision with a ball of the same mass moving with velocity $2V$ towards it. Taking direction of $V$ as positive velocities of the two balls after collision are
Which of the following statements is true
A mass of $20\, kg$ moving with a speed of $10\,m/s$ collides with another stationary mass of $5\,kg.$ As a result of the collision, the two masses stick together. The kinetic energy of the composite mass will be ............. $J$