The maximum value of the applied force $F$ such that the block as shown in the arrangement does not move is (Acceleration due to gravity, $g=10 \,ms^{-2}$) (in $\,N$)

$A$ heavy box is to be dragged along a rough horizontal floor. Person $A$ pushes it at an angle of $30^\circ$ from the horizontal and requires a minimum force $F_A$. Person $B$ pulls the box at an angle of $60^\circ$ from the horizontal and needs a minimum force $F_B$. If the coefficient of friction between the box and the floor is $\mu = \frac{\sqrt{3}}{5}$,find the ratio $\frac{F_A}{F_B}$.

$A$ block of mass $m$ is pressed against a vertical surface by a spring of unstretched length $l$. The spring is compressed by a distance $d$ as shown in the figure. If the coefficient of friction between the block and the surface is $\mu$,choose the correct statement.

As shown in the figure, a block of mass $10 \ kg$ lying on a horizontal surface is pulled by a force $F$ acting at an angle $30^{\circ}$ with the horizontal. For $\mu_{s} = 0.25$, the block will just start to move for the value of $F$: [Given $g = 10 \ ms^{-2}$] (in $N$)

$A$ block of mass $M$ rests on a rough horizontal table. $A$ steadily increasing horizontal force is applied such that the block starts to slide on the table without toppling. The force is continued even after sliding has started. Assume the coefficients of static and kinetic friction between the table and the block to be equal. The correct representation of the variation of the frictional force $f$,exerted by the table on the block with time $t$ is given by

The limiting friction is