The coefficient of friction $\mu$ and the angle of friction $\lambda$ are related as

$A$ body of mass $m$ rests on a horizontal surface. The coefficient of friction between the body and the surface is $\mu$. If the mass is pulled by a force $P$ at an angle of $30^{\circ}$ with the horizontal as shown in the figure,the limiting friction between the body and the surface will be:

$A$ block of mass $M$ is being pulled along a rough horizontal surface. The coefficient of friction between the block and the surface is $\mu$. If another block of mass $M/2$ is placed on the block and it is again pulled on the surface,the coefficient of friction between the block and the surface will be

$A$ force $\vec{F} = \hat{i} + 4\hat{j} \text{ N}$ acts on the $1 \text{ kg}$ block shown in the figure. The coefficient of friction between the block and the surface is $\mu = 0.3$. The force of friction acting on the block is:

$A$ pulling force $F$ making an angle $\theta$ with the horizontal is applied on a block of weight $W$ placed on a horizontal table. If the angle of friction is $\alpha$,then the magnitude of the force required to move the body is equal to

Write the unit of the coefficient of static friction.