If a force of $250\, N$ acts on a body,the momentum acquired is $125\, kg \cdot m/s$. What is the period for which the force acts on the body? ......... $s$

$A$ particle of mass $1\, kg$ is acted upon by a force $F$ which varies as shown in the figure. If the initial velocity of the particle is $10\, ms^{-1}$, the maximum velocity attained by the particle during the period is ........ $ms^{-1}$.

$1000$ small balls,each weighing $1 \text{ g}$,strike $1 \text{ cm}^2$ of area per second with a velocity of $50 \text{ m/s}$ in a normal direction and rebound with the same velocity. The value of pressure on the surface will be:

In the figure,the position-time graph of a particle of mass $0.1\, kg$ is shown. The impulse at $t = 2\, s$ is ......... $kg\, m/s$.

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 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 $kg \cdot m/s$)