$A$ block of mass $0.1 \, kg$ is held against a wall by applying a horizontal force of $5 \, N$ on the block. If the coefficient of friction between the block and the wall is $0.5$,the magnitude of the frictional force acting on the block is ........ $N$.

$A$ box when dropped from a certain height reaches the ground with a speed $v$. When it slides from rest from the same height down a rough inclined plane inclined at an angle $45^{\circ}$ to the horizontal,it reaches the ground with a speed $v/3$. The coefficient of sliding friction between the box and the plane is:

The coefficient of friction between two surfaces is $\mu = 0.8$. The tension in the string shown in the figure is ........ $N$.

$A$ block of mass $m$ is placed on a surface having a vertical cross-section given by $y = x^2 / 4$. If the coefficient of friction is $0.5$,the maximum height above the ground at which the block can be placed without slipping is:

If the coefficient of friction between an insect and a bowl is $\mu$ and the radius of the bowl is $r$,the maximum height to which the insect can crawl in the bowl is:

$A$ body is moving up an inclined plane of angle $\theta$ with an initial kinetic energy $E$. The coefficient of friction between the plane and the body is $\mu$. The work done against friction before the body comes to rest is