The retarding acceleration of $7.35\, ms^{-2}$ due to frictional force stops a car of mass $400\, kg$ travelling on a road. The coefficient of friction between the tyre of the car and the road is

$A$ body of mass $2$ kg is moving on the ground and comes to rest after some time. The coefficient of kinetic friction between the body and the ground is $0.2$. The retardation in the body is ...... $m/s^2$.

$A$ bag is gently dropped on a conveyor belt moving at a speed of $2\,m/s$. The coefficient of friction between the conveyor belt and the bag is $0.4$. Initially,the bag slips on the belt before it stops slipping due to friction. The distance travelled by the bag on the belt during the slipping motion is $.....m$. [Take $g=10\,m/s^{-2}$]

$A$ man slides down a telegraphic pole with an acceleration equal to one-fourth of the acceleration due to gravity. The frictional force between the man and the pole is equal to which of the following in terms of the man's weight $w$?

$A$ block of $7\,kg$ is placed on a rough horizontal surface and is pulled by a variable force $F$ (in $N$) $= 5t$,where $t$ is time in seconds,at an angle of $37^{\circ}$ with the horizontal as shown in the figure. The coefficient of static friction between the block and the surface is $\mu = 1$. If the force starts acting at $t = 0\,s$,find the time at which the block starts to slide. (Take $g = 10\,m/s^2$)

$A$ block of a certain mass is placed on a rough floor. The coefficients of static and kinetic friction between the block and the floor are $0.4$ and $0.25$ respectively. $A$ constant horizontal force $F = 20 \text{ N}$ acts on it so that the velocity of the block varies with time according to the following graph. The mass of the block is nearly (Take $g = 10 \text{ m/s}^2$): (in $\text{ kg}$)