$A$ block of mass $1\, kg$ lies on a horizontal surface in a truck. The coefficient of static friction between the block and the surface is $0.6$. If the acceleration of the truck is $5\, m/s^2$,the frictional force acting on the block is ........ $N$.

The coefficient of friction between blocks $A$ and $B$ is $\mu$. The minimum force $F$ with which $A$ must be pushed such that $B$ will not slip down is

Two blocks $(A)$ of $2\,kg$ and $(B)$ of $5\,kg$ rest one over the other on a smooth horizontal plane. The coefficient of static and dynamic friction between $(A)$ and $(B)$ is the same and equal to $0.60$. Find the maximum horizontal force that can be applied to $(B)$ such that both $(A)$ and $(B)$ do not have any relative motion. $(g = 10\,m/s^2)$

Block $A$ weighing $100 \, kg$ rests on a block $B$ and is tied with a horizontal string to the wall at $C$. Block $B$ weighs $200 \, kg$. The coefficient of friction between $A$ and $B$ is $0.25$ and between $B$ and the surface is $1/3$. The horizontal force $P$ necessary to move the block $B$ should be ........ $N$ $(g = 10 \, m/s^2)$.

Two blocks $A$ and $B$ of masses $5 \,kg$ and $3 \,kg$ respectively rest on a smooth horizontal surface with $B$ over $A$. The coefficient of friction between $A$ and $B$ is $0.5$. The maximum horizontal force (in $kg \,wt.$) that can be applied to $A$,so that there will be motion of $A$ and $B$ without relative slipping,is

Two blocks $A$ and $B$ of masses $4 \ kg$ and $6 \ kg$ are as shown in the figure. $A$ horizontal force of $12 \ N$ is required to make $A$ slip over $B$. Find the maximum horizontal force $F_B$ that can be applied on $B$ so that both $A$ and $B$ move together. (Take $g=10 \ m \ s^{-2}$) (in $N$)