The time in which a force of $2 \, N$ produces a change of momentum of $0.4 \, kg \cdot m/s$ in a body is ......... $s$.

An object of mass $5 \ kg$ is moving with a momentum of $10 \ kg \cdot m/s$. If a force of $0.2 \ N$ is applied on it in the direction of its motion for $10 \ s$,what is the increase in its kinetic energy in $Joule$?

What is linear momentum? Represent it in formula form.

$A$ bullet of $4 \, g$ mass is fired from a gun of mass $4 \, kg$. If the bullet moves with the muzzle speed of $50 \, ms^{-1}$,the impulse imparted to the gun and the velocity of recoil of the gun are:

$A$ soccer ball of mass $250 \text{ g}$ is moving horizontally to the left with a speed $22 \text{ ms}^{-1}$. This ball is kicked towards the right with a velocity $30 \text{ ms}^{-1}$ at an angle $53^{\circ}$ with the horizontal in the upward direction. Assuming that it took $0.01 \text{ s}$ for the collision to take place, the average force acting is $(\cos 53^{\circ} = \frac{3}{5}; \sin 53^{\circ} = \frac{4}{5})$. (in $\text{ N}$)

In an hour-glass,approximately $100$ grains of sand fall per second (starting from rest); and it takes $2 \, s$ for each sand particle to reach the bottom of the hour-glass. If the average mass of each sand particle is $0.2 \, g$,then the average force exerted by the falling sand on the bottom of the hour-glass is close to .......... $N$.