$A$ 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 $w$?

Which one of the following statements is correct?

The coefficient of friction between the block of mass ${M_1}$ and the surface is $\mu$. When the system is released,it moves with acceleration. What mass $m$ should be placed on the block ${M_1}$ so that the system moves with a constant velocity?

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):

$A$ wooden block of mass $M$ resting on a rough horizontal surface is pulled with a force $F$ at an angle $\phi$ with the horizontal. If $\mu$ is the coefficient of kinetic friction between the block and the surface,then the acceleration of the block is:

$A$ block of mass $5\, kg$ is kept on a rough horizontal floor. It is given a velocity $33\, m/s$ towards the right. $A$ force of $20\sqrt{2}\, N$ continuously acts on the block as shown in the figure. If the coefficient of friction between the block and the floor is $0.5$, the velocity of the block after $3\, seconds$ is ........ $m/s$ $(g = 10\, m/s^2)$.