$A$ body is moving along a rough horizontal surface with an initial velocity $6\,m/s$. If the body comes to rest after travelling $9\,m$,then the coefficient of sliding friction will be

$A$ body of mass $10 \,kg$ is kept on a rough horizontal surface with a coefficient of friction of $0.3$. If a horizontal force of $50 \,N$ is applied to the body, then the acceleration of the body is (Acceleration due to gravity $= 10 \,ms^{-2}$) (in $\,ms^{-2}$)

$A$ block of mass $40 \,kg$ slides over a surface,when a mass of $4 \,kg$ is suspended through an inextensible massless string passing over a frictionless pulley as shown below. The coefficient of kinetic friction between the surface and the block is $0.02$. The acceleration of the block is ............ $m/s^2$. (Given $g = 10 \,m/s^2$.)

Consider a block and trolley system as shown in the figure. If the coefficient of kinetic friction between the trolley and the surface is $0.04$,the acceleration of the system in $m/s^2$ is (Consider that the string is massless and unstretchable and the pulley is also massless and frictionless):

$A$ 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 $w$?

What is rolling friction? Write the laws of rolling friction. Define the coefficient of rolling friction.