A block pressed against the vertical wall is in equilibrium. The minimum coefficient of  friction is:-

In figure, the coefficient of friction between the floor and the block $B$ is $0.2$ and  between blocks $A$ and $B$ is $0.3$. ........ $N$  is the maximum horizontal force $F$ can be  applied to the block $B$ so that both blocks move together .

A block of mass $m$ is moving with a constant acceleration a on a rough plane. If the coefficient of friction between the block and ground is $\mu $, the power delivered by the external agent after a time $t$ from the beginning is equal to

A man balances himself in a horizontal position by pushing his hands and feet against two parallel walls. His centre of mass lies midway between the walls. The coefficients of friction at the walls are equal. Which of the following is not correct?

If mass of $A = 10\,\,kg$, coefficient of static friction $= 0.2$, coefficient of kinetic friction = $0.2$. Then mass of $B$ to start motion is

A body of weight $50 \,N$ placed on a horizontal surface is just moved by a force of $28.2\, N$. The frictional force and the normal reaction are