If $100 \mathrm{N}$ force is applied on the block. Then, frictional force acting on the block will be (in Newton),

A block of mass $200 \mathrm{kg}$ is being pulled by some men, up an inclined plane of inclination $45°$ and coefficient of friction $0.5$, as shown in the figure. If each man can apply a maximum force of $500 \mathrm{N}$, then the minimum number of men required to just slide the block, up the plane is

A man of mass $60 \mathrm{kg}$ is standing on a horizontal conveyor belt (see figure). When the belt is given an acceleration of $1 \mathrm{m} {\mathrm{s}}^{-2}$, the man remains stationary with respect to the moving belt. If $g=10 \mathrm{m} {\mathrm{s}}^{-2}$.

As shown in the figure, $M$ is a man of mass $60 \mathrm{kg}$ standing on a block of mass $40 \mathrm{kg}$ kept on the ground. The coefficient of friction between the feet of the man and the block is $0.3$ and that between $B$ and the ground is $0.1$. If the man accelerates with an acceleration $2 \mathrm{m} {\mathrm{s}}^{-2}$ in the forward direction, then

A boy of mass$50 \mathrm{kg}$produces an acceleration of $2 \mathrm{m} {\mathrm{s}}^{-2}$ in a block of mass$20 \mathrm{kg}$ by pushing it on the horizontal direction. The boy moves with the block such that the boy and the block have the same acceleration. There is no friction between the block and fixed horizontal surface but there is friction between the foot of the boy and horizontal surface. Find frictional force (in $\mathrm{N}$) exerted by the horizontal surface on the boy.

A block of mass m is placed on a rough inclined plane. The coefficient of friction between the block and the plane is $\mu$ and the inclination of the plane is$\theta$. Initially $\theta =0$ and the block will, remain stationary on the plane. Now the inclination $\theta$is gradually increased. 

For what value of $\mathrm{\theta }$ will the block slide on the inclined plane?