A block of mass $5\, kg$ is on a rough horizontal surface and is at rest. Now a force of $24\, N $is imparted to it with negligible impulse. If the coefficient of kinetic friction is $0.4$ and $g = 9.8\,m/{s^2}$, then the acceleration of the block is ........ $m/s^2$

Meena applies the front brakes, while riding on her bicycle along a flat road. The force that slows her bicycle is provided by the

An inclined plane is bent in such a way that the vertical cross-section is given by $y =\frac{ x ^{2}}{4}$ where $y$ is in vertical and $x$ in horizontal direction. If the upper surface of this curved plane is rough with coefficient of friction $\mu=0.5,$ the maximum height in $cm$ at which a stationary block will not slip downward is............$cm$

A block of mass $M$ is held against a rough vertical well by pressing it with a finger. If the coefficient of friction between the block and the wall is $\mu $ and acceleration due to gravity is $g$, calculate the minimum force required to be applied by the finger to hold the block against the wall.

$Assertion$ : On a rainy day it is difficult to drive a car or bus at high speed.
$Reason$ : The value of coefficient of friction is lowered due to wetting of the surface

If the normal force is doubled, the coefficient of friction is