If the normal reaction is $R$ and the coefficient of friction is $\mu$,what is the work done against friction in moving a body by a distance $d$ slowly?

$A$ block of mass $M = 5\,kg$ is resting on a rough horizontal surface for which the coefficient of friction is $0.2$. When a force $F = 40\,N$ is applied at an angle of $30^\circ$ with the horizontal,the acceleration of the block will be ........ $m/s^2$ $(g = 10\,m/s^2)$.

$A$ body of $10\, kg$ is acted upon by a force of $129.4\, N$. If $g = 9.8\, m/s^2$ and the acceleration of the block is $10\, m/s^2$,what is the coefficient of kinetic friction?

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

$A$ body of weight $64 \,N$ is pushed with just enough force to start it moving across a horizontal floor and the same force continues to act afterwards. If the coefficients of static and dynamic friction are $0.6$ and $0.4$ respectively, the acceleration of the body is (Acceleration due to gravity $= g$)

$A$ $1\,kg$ block is being pushed against a wall by a force $F = 75\,N$ as shown in the Figure. The coefficient of friction is $0.25.$ The magnitude of acceleration of the block is ........ $m/s^2$. (Take $g = 10\,m/s^2$)