The coefficient of static friction,$\mu_s$,between block $A$ of mass $2\, kg$ and the table as shown in the figure is $0.2$. Find the maximum mass value of block $B$ in $kg$ so that the two blocks do not move. The string and the pulley are assumed to be smooth and massless. $(g = 10\, m/s^2)$

If the coefficient of friction is $\sqrt{3}$,what is the angle of friction between the two surfaces in contact (in $^{\circ}$)?

$A$ box of mass $2 kg$ is placed on the roof of a car. The box would remain stationary until the car attains a maximum acceleration. The coefficient of static friction between the box and the roof of the car is $0.2$ and $g=10 ms^{-2}$. This maximum acceleration of the car,for the box to remain stationary,is: (in $ms^{-2}$)

Static friction between two surfaces:

$A$ block of mass $M$ is placed on a horizontal surface and it is tied with an inextensible string to a block of mass $m$,as shown in the figure. $A$ block of mass $m_0$ is also placed on $M$. If $\mu$ is the coefficient of friction between the block $M$ and the horizontal surface,then the minimum value of $m_0$ required to keep the block $m$ stationary is

$A$ horizontal force of $10 \, N$ is necessary to just hold a block stationary against a wall. The coefficient of friction between the block and the wall is $0.2$. The weight of the block is ........ $N$.