If ${\mu _s}$,${\mu _k}$,and ${\mu _r}$ are coefficients of static friction,sliding (kinetic) friction,and rolling friction respectively,then:

What can be inferred from the relation $f_S \leqslant \mu_S N$?

$A$ block of mass $4 \text{ kg}$ is placed on a horizontal surface having coefficients of static and kinetic friction as $0.5$ and $0.4$ respectively. If a force of $4 \text{ N}$ is applied parallel to the horizontal surface, then the force of friction acting on the body will be $\left[g = 10 \text{ m/s}^2\right]$ (in $\text{ N}$)

$A$ body of weight $50 \,N$ is placed on a horizontal surface as shown in the figure. The minimum force required to move the body is $28.28 \,N$. The frictional force and the normal reaction are respectively.

$A$ block of mass $M$ is placed on a rough surface with a coefficient of friction $\mu = 3$. If the applied force $F$ is $(4/5)$ of the minimum force required to just move the block,find the total force exerted by the ground on the block.

The limiting friction between two bodies in contact is independent of