$A$ ball of mass $3 \ kg$,moving with a speed of $100 \ m/s$,strikes a wall at an angle of $60^{\circ}$ with the wall (as shown in the figure). The ball rebounds at the same speed and remains in contact with the wall for $0.2 \ s$. The force exerted by the ball on the wall is:

Pick out the only vector quantity in the following list:
Temperature,pressure,impulse,time,power,total path length,energy,gravitational potential,coefficient of friction,charge.

An object of mass $m \, kg$ with speed $v \, m/s$ strikes a wall at an angle $\theta$ with the normal and rebounds at the same speed and same angle. The magnitude of the change in momentum of the object will be

$A$ 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 ............

$A$ small mass $m$ is launched from the top of a cliff with speed $V$ at an angle of $30^{\circ}$ above the horizontal. When the mass reaches the ground,its velocity is directed at $45^{\circ}$ below the horizontal. Which one of the following choices is the magnitude of the total impulse that was imparted to the mass during its flight? Ignore air resistance.

Which type of forces are responsible for the explosion of a chemical bomb: internal or external forces?