A body of mass $1\, kg$ rests on a horizontal floor with which it has a coefficient of static friction $\frac{1}{\sqrt{3}}$. It is desired to make the body move by applying the minimum possible force $F\, N$. The value of $F$ will be the Nearest Integer) [Take $g =10 \,ms ^{-2}$ ]
$15$
$7$
$5$
$10$
The retarding acceleration of $7.35\, ms^{-2}$ due to frictional force stops the car of mass $400\, kg$ travelling on a road. The coefficient of friction between the tyre of the car and the road is
The rear side of a truck is open and a box of $40 \;kg$ mass is placed $5 \,m$ away from the open end as shown in Figure. The coeffictent of friction between the box and the surface below it is $0.15 .$ On a stratght road, the truck starts from rest and accelerates with $2\; m s ^{-2} .$ At what distance from the starting point does the box fall off the truck? (Ignore the size of the box).
A pen of mass $m$ is lying on a piece of paper of mass $M$ placed on a rough table. If the coefficients of friction between the pen and paper and the paper and the table are $\mu_1$ and $\mu_2$, respectively. Then, the minimum horizontal force with which the paper has to be pulled for the pen to start slipping is given by
A coin placed on a rotating table just slips when it is placed at a distance of $1\,cm$ from the center. If the angular velocity of the table in halved, it will just slip when placed at a distance of from the centre $............\,cm$
A force acts on a block as shown in figure. Find time when block loses contact with surface.