The blocks shown in the figure move with a constant velocity of $10 \, m/s$ towards the right. All surfaces in contact are rough. The friction force applied by the ground on block $B$ is ........ $N$.

$A$ 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 $.........\,m/s^2$.

What is the maximum value of the force $F$ such that the block shown in the arrangement does not move (in $N$)? (Given $m = \sqrt{3} \ kg$,$\mu = \frac{1}{2\sqrt{3}}$,$g = 10 \ m/s^2$)

$A$ $60\, kg$ body is pushed with just enough force to start it moving across a floor and the same force continues to act afterwards. The coefficient of static friction and sliding friction are $0.5$ and $0.4$ respectively. The acceleration of the body is ........ $m/s^2$. (Take $g = 10\, m/s^2$)

$A$ block of mass $5 \ kg$ is placed on a rough horizontal surface having a coefficient of friction $0.5$. If a horizontal force of $60 \ N$ is acting on it,then the acceleration of the block is (Acceleration due to gravity,$g = 10 \ ms^{-2}$). (in $ms^{-2}$)

$A$ block of mass $m$ rests on a rough horizontal surface as shown in the figure. The coefficient of friction between the block and the surface is $\mu$. $A$ force $F = mg$ acting at an angle $\theta$ with the vertical side of the block pulls it. In which of the following cases can the block be pulled along the surface?