Match the items in Column-$I$ with those in Column-$II$.

Column-$I$	Column-$II$
$(1)$ Newton's third law of motion	$(a)$ $\vec{F}_{12} = -\vec{F}_{21}$
$(2)$ Law of conservation of momentum	$(b)$ $\Delta \vec{p} = 0$
	$(c)$ $\vec{F}_{12} = \vec{F}_{21}$

The pulleys and strings shown in the figure are smooth and of negligible mass. For the system to remain in equilibrium,the angle $\theta$ should be ........ $^o$.

$A$ gardener holds a hosepipe through which water is gushing out at a rate of $4\, kg\, s^{-1}$ with a speed of $2\, ms^{-1}$. The moment the speed of water is increased to $3\, ms^{-1}$,the gardener will experience a jerk of

Consider the following statements $A$ and $B$ and identify the correct answer:
$A$. When a person walks on a rough surface,the direction of the frictional force exerted by the surface on the person is in the same direction as his motion.
$B$. When a cycle is in motion,the force of friction exerted by the ground on the front wheel is in the backward direction.

Imagine a situation in which the horizontal surface of block $M_0$ is smooth and its vertical surface is rough with a coefficient of friction $\mu$. In the above problem,choose the correct value$(s)$ of $F$ for which the blocks $M$ and $m$ remain stationary with respect to $M_0$.

Match Column-$I$ with Column-$II$ correctly.

Column-$I$	Column-$II$
$(1)$ Static friction	$(a)$ Limiting friction
$(2)$ Rolling friction	$(b)$ Ball bearing
	$(c)$ Object moving on a road