$A$ machine gun fires $20$ bullets per second into a target. Each bullet weighs $150 \, g$ and has a speed of $800 \, m/s$. Find the force necessary to hold the gun in position.

$A$ particle of mass $2 \ kg$ is initially at rest. $A$ force acts on it whose magnitude changes with time. The force-time graph is shown below. The velocity of the particle after $10 \ s$ is $.... \ ms^{-1}$.

Consider the following statement: When jumping from some height,you should bend your knees as you come to rest,instead of keeping your legs stiff. Which of the following relations can be useful in explaining the statement?

$A$ ball hits a vertical wall horizontally at $10 \ m/s$ and bounces back at $10 \ m/s$. Which of the following statements is correct?

In two different experiments,an object of mass $5 \; kg$ moving with a speed of $25 \; ms^{-1}$ hits two different walls and comes to rest within
$(i)$ $3 \; s$,$(ii)$ $5 \; s$,respectively.
Choose the correct option out of the following:

$A$ particle moves in the $x-y$ plane under the action of a force $\vec F$ such that the value of its linear momentum $\vec P$ at any time $t$ is $P_x = 2 \cos t$ and $P_y = 2 \sin t$. The angle between $\vec F$ and $\vec P$ at a given time $t$ will be: