Three different projectiles, each with the same mass, are fired with speed $v$ at a wall. In case $A,$ the projectile bounces straight back with speed $v.$ In case $B$, the projectile sticks to the wall. In case $C$, the projectile crashes through the wall and emerges with half its original speed. These three cases are shown here.

Place the impulse exerted by the wall on the projectile in each of these three cases in the correct order.

If a rubber ball falls from a height $h$ and rebounds upto the height of $h / 2$. The percentage loss of total energy of the initial system as well as velocity ball before it strikes the ground, respectively, are :

A point mass of $1 \mathrm{~kg}$ collides elastically with a stationary point mass of $5 \mathrm{~kg}$. After their collision, the $1 \mathrm{~kg}$ mass reverses its direction and moves with a speed of $2 \mathrm{~ms}^{-1}$. Which of the following statement(s) is (are) correct for the system of these two masses?

$(A)$ Total momentum of the system is $3 \mathrm{~kg} \mathrm{~ms}^{-1}$

$(B)$ Momentum of $5 \mathrm{~kg}$ mass after collision is $4 \mathrm{~kg} \mathrm{~ms}^{-1}$

$(C)$ Kinetic energy of the centre of mass is $0.75 \mathrm{~J}$

$(D)$ Total kinetic energy of the system is $4 \mathrm{~J}$

$A$ bal $A$ collides elastically with another identical ball $B$ initially at rest $A$ is moving with velocity of $10m/ s$ at an angle of $60^o$ from the line joining their centres. Select correct alternative :

Write the equation of mass energy equivalence.

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