The tension $T$ in the string shown in figure is

A block of mass $1\, kg$ is at rest on a horizontal table. The coefficient of static friction  between the block and the table is $0.5.$ The magnitude of the force acting upwards at  an angle of $60^o$ from the horizontal that will just start the block moving is

Given in the figure are two blocks $A$ and $B$ of weight $20\, N$ and $100\, N$, respectively. These are being pressed against a wall by a force $F$ such that the system does not slide as shown. If the coefficient of friction between the blocks is $0.1$ and between block $B$ and the wall is $0.15$, the frictional force applied by the wall on block $B$ is ........ $N$

What is friction ? Explain static frictional force.

A body of mass m rests on horizontal surface. The coefficient of friction between the body and the surface is $\mu .$ If the mass is pulled by a force $P$ as shown in the figure, the limiting friction between body and surface will be

The limiting value of static friction between two contact surfaces is ...........