Exercise 4.6

A block of mass $2 \mathrm{kg}$ is placed on the floor $(\mu =0.4).$ A horizontal force of $7 \mathrm{N}$ is applied on the block. The force of friction between the block and floor is

Find the contact force on the block having mass $1 \mathrm{kg}.$ (Assume wedge to be fixed)

The coefficient of friction of a surface is $\frac{1}{\sqrt{3}}.$ What should be the angle of inclination so that a body placed on the surface just begins to slide down?

A block stays in equilibrium on an inclined plane. It is easiest to push along

A block is in equilibrium. The tension in the string is $(\mu <\tan \theta )$

A force $P=3mg$ acts on a block of mass $m$ at an angle of $30°$ with horizontal. The friction force between the block and ground (assuming $\mu =$ coefficient of friction between the contacting surface) is

A block is placed on a rough horizontal surface. The minimum force required to slide the block is

A bus starts from rest and travels a distance $s$ along a straight horizontal road. The coefficients of static and kinetic friction between the road and the tyres are ${\mu }_s$ and ${\mu }_k$ respectively. The minimum time of travel is proportional to