$A$ force is applied to a body of mass $2 \,kg$ at rest on a frictionless horizontal surface, as shown in the force-time $(F-t)$ graph. The speed of the body after $1 \,s$ is: (in $\,m/s$)

$A$ force of $10 \, N$ acts on a body of mass $20 \, kg$ for $10 \, s$. The change in its momentum is ........... $kg \cdot m/s$.

$A$ ball of mass $3 \ kg$ strikes a wall with a velocity of $10 \ m/s$ at an angle of $30^\circ$ with the normal to the wall and rebounds at the same angle and speed. What is the change in momentum of the ball in $MKS$ units?

Define impulse of force. Time derivative of momentum gives which physical quantity?

$A$ machine gun fires a bullet of mass $65 \, g$ with a velocity of $1300 \, m/s$. The man holding it can exert a maximum force of $169 \, N$ on the gun. The number of bullets he can fire per second will be ............

$A$ machine gun fires a bullet of mass $35 \ g$ with a speed of $600 \ m/s$. The person holding the gun can exert a maximum force of $147 \ N$ on it. The number of bullets that can be fired from the gun per second is