$A$ heavy box of mass $50 \,kg$ is moving on a horizontal surface. If the coefficient of kinetic friction between the box and the horizontal surface is $0.3$, then the force of kinetic friction is: (in $\,N$)

$A$ 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 $0.8$ and $0.6$ respectively,then the acceleration of the body will be

$A$ body of mass $2 \, kg$ is kept by pressing it against a vertical wall by a force of $100 \, N$. The coefficient of friction between the wall and the body is $0.3$. Then the frictional force is equal to ........ $N$.

For the given figure,find the acceleration of the $40\, kg$ block in $m/s^2$. (Take $g = 10\, m/s^2$)

$A$ body of mass $40\,kg$ resting on a rough horizontal surface is subjected to a force $P$ which is just enough to start the motion of the body. If $\mu_{s} = 0.5$,$\mu_{k} = 0.4$,$g = 10\,m/s^2$,and the force $P$ is continuously applied on the body,then the acceleration of the body is $.........\,m/s^2$.

Consider a car moving along a straight horizontal road with a speed of $72 \, km/h$. If the coefficient of kinetic friction between the tyres and the road is $0.5$,the shortest distance in which the car can be stopped is ........ $m$. $[g = 10 \, m/s^2]$