When the speed of a moving body is doubled:

$A$ machine gun fires a bullet of mass $40\,g$ with a velocity $1200\,m/s$. The man holding it can exert a maximum force of $144\,N$ on the gun. How many bullets can he fire per second at the most?

In projectile motion,two particles of masses $m_1$ and $m_2$ have velocities $\vec{V}_1$ and $\vec{V}_2$ respectively at time $t=0$. Their velocities become $\vec{V}_1^{\prime}$ and $\vec{V}_2^{\prime}$ at time $2t$ while still moving in air. The value of $[(m_1 \vec{V}_1^{\prime} + m_2 \vec{V}_2^{\prime}) - (m_1 \vec{V}_1 + m_2 \vec{V}_2)]$ is ($g =$ acceleration due to gravity).

$A$ machine gun fires a bullet of mass $40$ g with a speed of $600$ m/s. The person holding the gun can bear a maximum force of $168$ $N$ on it. The number of bullets that can be fired from the gun per second is

The figure below shows the position-time graph of a body of mass $0.04 \; kg$. Suggest a suitable physical context for this motion. What is the time between two consecutive impulses received by the body? What is the magnitude of each impulse?

$A$ ball of mass $0.15 \, kg$ is dropped from a height $10 \, m$,strikes the ground,and rebounds to the same height. The magnitude of the impulse imparted to the ball is $(g = 10 \, m/s^2)$ nearly: (in $kg \cdot m/s$)