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 ........ $^o$.

State whether the following statements are true or false:
$(a)$ Momentum and the change in momentum are always in the same direction.
$(b)$ Action force and reaction force always act simultaneously and on the same body.
$(c)$ The maximum static frictional force depends on the area of the contact surface.

On which factors does the stopping distance of a vehicle depend?

In the figure, two blocks are connected by a uniform strut attached to each block with frictionless pins. Block $A$ weighs $400 \, N$, block $B$ weighs $300 \, N$, and the strut $AB$ weighs $200 \, N$. If $\mu = 0.25$ under block $B$, determine the minimum coefficient of friction under block $A$ to prevent motion.

When a body moves with some friction on a surface,

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