$A$ block of mass $2 \, kg$ is placed on a surface with a coefficient of friction $\mu = 0.4$. If a force of $2.5 \, N$ is applied to it,the frictional force will be ........ $N$.

The limiting friction is

$A$ block placed on a rough horizontal surface is pulled by a horizontal force $F$. Let $f$ be the force applied by the rough surface on the block. Plot a graph of $f$ versus $F$.

Block $B$ lying on a table weighs $W$. The coefficient of static friction between the block and the table is $\mu$. Assume that the cord between $B$ and the knot is horizontal. The maximum weight of the block $A$ for which the system will be stationary is

$A$ block of mass $m$ lying on a rough horizontal plane is acted upon by a horizontal force $P$ and another force $Q$ inclined at an angle $\theta$ to the vertical. The minimum value of the coefficient of friction between the block and the surface for which the block will remain in equilibrium is

If the coefficient of friction is $\sqrt{3}$,what is the angle of friction between the two surfaces in contact (in $^{\circ}$)?