A force acts on a block as shown in figure. Find time when block loses contact with surface.

A uniform rope lies on a horizontal table so that a part of it hangs over the edge. The rope begins to slide down when the length of the hanging part is $25\%$ of the entire length. The coefficient of friction between the rope and the table is

The limiting friction between two bodies in contact is independent of

A rope of length $L$ and mass $M$ is being pulled on a rough horizontal floor by a constant horizontal force $F$ = $Mg$ . The force is acting at one end of the rope in the same direction as the length of the rope. The coefficient of kinetic friction between rope and floor is $1/2$ . Then, the tension at the midpoint of the rope is

A heavy body of mass $25\, kg$ is to be dragged along a horizontal plane $\left( {\mu  = \frac{1}{{\sqrt 3 }}} \right).$ The least force required is ........ $kgf$ 

A force $f$ is acting on a block of mass $m$. Coefficient of friction between block and surface is  $\mu$. The block can be pulled along the surface if :-