$A$ block of mass $5 \,kg$ moving on a rough surface with a velocity of $4 \,ms^{-1}$ is stopped by friction in $2 \,s$. The coefficient of friction between the contact surfaces is (Acceleration due to gravity $g = 10 \,ms^{-2}$)

$A$ 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 $w$?

$A$ body of mass $m$ moves with a velocity $v$ on a surface whose friction coefficient is $\mu$. If the body covers a distance $s$ before coming to rest,what is the initial velocity $v$?

$A$ block of weight $W$ is kept on a rough horizontal surface (friction coefficient $\mu$). Two forces of magnitude $W/2$ each are applied as shown in the figure. Choose the $\text{CORRECT}$ statement:

Explain kinetic friction. Write the laws of kinetic friction. Define the coefficient of kinetic friction.

$A$ block of mass $4\,kg$ is placed on a rough horizontal plane. $A$ time-dependent force $F = kt^2$ acts on the block,where $k = 2\,N/s^2$. The coefficient of friction is $\mu = 0.8$. The force of friction between the block and the plane at $t = 2\,s$ is ....... $N$.