Quick sand consists of very smooth and tiny grains of sand. What would happen if a man or a heavy animal steps over a patch of such sand in a desert?

Amar, Javed, and Rita were riding in a bus that was moving with a high velocity on a highway when a bug hit the windshield and its dead body got stuck on the windscreen. Amar and Javed began discussing the situation. Amar suggested that the change in momentum of the bug is much greater than that of the bus. After all, argued Amar, there was no noticeable change in the velocity of the bus compared to the obvious change in the velocity of the bug. Javed opined that since the bus was moving with a larger velocity, so it exerted a larger force on the bug, as a result of which it died. Rita disagreed entirely, arguing that both the bug and bus experienced the same force and a change in their momentum. Who do you agree with? Support your answer.

$A$ machine gun can fire $50 \, g$ bullets with a velocity of $150 \, m s^{-1}$. $A$ $60 \, kg$ stone is moving towards the machine gun with a velocity of $10 \, m s^{-1}$. How many bullets must be fired from the gun to just stop the stone in its tracks?

When a carpet is beaten with a stick,it releases dust. Explain why?

$A$ large truck and a mini bus both moving with a velocity of magnitude $V$ have a head-on collision and both of them come to a halt after that. If the collision lasts for $1 \, s$:
$(a)$ Which vehicle experiences the greater force of impact?
$(b)$ Which vehicle experiences the greater change in momentum?
$(c)$ Which vehicle experiences the greater acceleration?

The momentum of a body of given mass is proportional to its