When a body slides down from rest along a smooth inclined plane making an angle of $45^o$ with the horizontal, it takes time $T$. When the same body slides down from rest along a rough inclined plane making the same angle and through the same distance, it is seen to take time $pT$, where $p$ is some number greater than $1$. Calculate the coefficient of friction between the body and the rough plane.

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

When slope (incline) is smooth as show

$\mathrm{F}=m a$

$\mathrm{~F}=m g \sin \theta$

$\therefore m a=m g \sin \theta$

$a =g \sin \theta$

$\theta =45^{\circ}$

$a=g\left(\frac{1}{\sqrt{2}}\right)$

Let distance covered by body be $d$

$d=u t+\frac{1}{2} a t^{2}$

$u=0 \text { let } t=\mathrm{T}$

$d=\frac{1}{2}\left(\frac{g}{\sqrt{2}}\right) \mathrm{T}^{2}$

$d=\frac{g \mathrm{~T}^{2}}{2 \sqrt{2}}$

When body moves on rough incline,

$f =\mu \mathrm{N}$

$=\mu m g \cos \theta$

Net force,

$=\mu g \sin \theta-\mu m g \cos \theta$

$=m(g \sin \theta-\mu g \cos \theta)$

$=m g(\sin \theta-\mu \cos \theta)$

$\mathrm{F} =m a^{\prime}$

$a^{\prime} =\text { effective acceleration, }$

$m a^{\prime} =m g(\sin \theta-\mu \cos \theta)$

$a^{\prime} =g(\sin \theta-\mu \cos \theta)$

$\theta =45$

n in figure boyd slides on slope,

886-s190

Similar Questions

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.

The coefficient of static friction, $\mu _s$ between block $A$ of mass $2\,kg$ and the table as shown in the figure is $0.2$. What would be the maximum mass value of block $B$ so that the two blocks $B$ so that the two blocks do not move? The string and the pulley are assumed to be smooth and masseless ....... $kg$ $(g = 10\,m/s^2)$

Abody is placed on a rough inclined plane of inclination $\theta$ .As the angle $\theta$ is increased from $0^o$ to $90^o$ the contact force between the block and the plane

A block of weight $W$ is kept on a rough horizontal surface (friction coefficient $\mu$). Two forces $W/2$ each are applied as shown in the figure. Choose the $CORRECT$ statement :-

A uniform rope of length l lies on a table. If the coefficient of friction is $\mu $, then the maximum length ${l_1}$ of the part of this rope which can overhang from the edge of the table without sliding down is