A force $\vec{F}=\hat{i}+4 \hat{j}$ acts on the block shown. The force of friction acting on the block is

Block $B$ of mass $100 kg$ rests on a rough surface of friction coefficient $\mu = 1/3$. $A$ rope is tied to block $B$ as shown in figure. The maximum acceleration with which boy $A$ of $25 kg$ can climbs on rope without making block move is:

A child weighing $25$ kg slides down a rope hanging from the branch of a tall tree. If the force of friction acting against him is $2\, N$,  ........ $m/s^2$ is the acceleration of the child (Take $g = 9.8\,m/{s^2})$

A bullet of mass $20\, g$ travelling horizontally with a speed of $500 \,m/s$ passes  through a wooden block of mass $10.0 \,kg$ initially at rest on a surface. The bullet  emerges with a speed of $100\, m/s$ and the block slides $20 \,cm$ on the surface  before coming to rest, the coefficient of friction between the block and the surface. $(g = 10\, m/s^2)$

For the given figure, if block remains in equilibrium position then find frictional force between block and wall ........ $N$

In the given figure the acceleration of $M$ is $(g = 10 \,ms^{-2})$