A block of mass $M$ is held against a rough vertical well by pressing it with a finger. If the coefficient of friction between the block and the wall is $\mu $ and acceleration due to gravity is $g$, calculate the minimum force required to be applied by the finger to hold the block against the wall.

Vedclass pdf generator app on play store
Vedclass iOS app on app store

Here, mass of the block $=\mathrm{M}$

Coefficient of friction between the block and the wall $=\mu$

Lef $F$ be force required to hold the block against the wall.

Figure show that weight of block $\mathrm{mg}$ is in downward direction and frictional force is in upward direction.

For equilibrium

$\therefore f=\mathrm{Mg}$

$\mathrm{F}=\mathrm{N}$

Frictional force $f=\mu \mathrm{N}$

$=\mu \mathrm{F}$

Comparing $(1)$ and $(2)$,

$\mathrm{mF}=\mathrm{Mg}$

$\mathrm{F}=\frac{\mathrm{Mg}}{\mu}$

886-s185

Similar Questions

A body of mass $2 \,kg$ is kept by pressing to a vertical wall by a force of $100\, N$. The coefficient of friction between wall and body is $0.3.$ Then the frictional force is equal to ........ $N$

In the diagram, $BAC$ is a rigid fixed rough wire and angle $BAC$ is $60^o$. $P$ and $Q$ are two identical rings of mass $m$ connected by a light elastic string of natural length $2a$ and elastic constant $\frac{mg}{a}$. If $P$ and $Q$ are in equilibrium when $PA = AQ = 3a$ then the least coefficient of friction between the ring and the wire is $\mu$. Then value of $\mu + \sqrt 3 $ is :-

A metal block is resting on a rough wooden surface. A horizontal force applied to the block is increased uniformly. Which of the following curves correctly represents velocity of the block ?

What is the maximum value of the force $F$ such that the block shown in the arrangement, does not move ........ $N$

  • [IIT 2003]

If for an inclined plane coefficient of static friction is ${\mu _s} = \frac{3}{4}$, then for the inclined plane angle of repose will be ........ $^o$