$A$ pendulum of length $2\,m$ is released from point $P$ as shown in the figure. When it reaches point $Q$,it loses $10\%$ of its total energy due to air resistance. The velocity at $Q$ is .... $m/s$.

$A$ ball is allowed to fall from a height of $10 \, m$. If there is $40 \%$ loss of energy due to impact,then after one impact the ball will rise to a height of ........ $m$.

$A$ particle of mass $m$ is at rest in a train moving with constant velocity with respect to the ground. Now,the particle is accelerated by a constant force $F_0$ acting along the direction of motion of the train for time $t_0$. $A$ girl in the train and a boy on the ground measure the work done by this force. Which of the following are $INCORRECT$?

If a skater of mass $3 \,kg$ has an initial speed of $32 \,m/s$ and a second skater of mass $4 \,kg$ has a speed of $5 \,m/s$. After a perfectly inelastic collision,they move together with a speed of $5 \,m/s$. Calculate the loss in kinetic energy.

Consider a one-dimensional collision involving a body of mass $m_1$ moving in the positive $x$ direction with speed $v_0$ and a second body of mass $m_2$ initially at rest. The collision can be completely inelastic,completely elastic,or partially inelastic. After the collision,$m_1$ moves with velocity $v_1$ and $m_2$ moves with velocity $v_2$. Determine the range of final velocity $v_1$ for the following cases:
$(A)$ If $m_1 > m_2$
$(B)$ If $m_1 < m_2$

In a one-dimensional collision between two particles,their relative velocity is $\vec{v}_1$ before the collision and $\vec{v}_2$ after the collision.