$A$ particle moves in the $x-y$ plane under the influence of a force $\vec{F}$ such that its linear momentum is $\vec{P}(t) = \hat{i} \cos(kt) - \hat{j} \sin(kt)$. If $k$ is a constant,the angle between $\vec{F}$ and $\vec{P}$ will be:

$A$ machine gun fires a bullet of mass $40\,g$ with a velocity $1200\,m/s$. The man holding it can exert a maximum force of $144\,N$ on the gun. How many bullets can he fire per second at the most?

$A$ bullet of mass $10\,g$ leaves the barrel of a gun with a velocity of $600\,m/s$. If the barrel of the gun is $50\,cm$ long and the mass of the gun is $3\,kg$,then the value of the impulse supplied to the gun will be $.....\,Ns$.

$A$ 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.

An engine pumps water continuously through a hose. Water leaves the hose with velocity $v$ and $m$ is the mass per unit length of the water jet. If this jet hits a surface and comes to rest instantaneously,the force on the surface is

Displacement of a particle of mass $2\, kg$ moving in a straight line varies with time as $s = (2t^3 + 2)\, m$. The impulse of the force acting on the particle over a time interval between $t = 0$ and $t = 1\, s$ is .......... $N-s$.