A man pulls a block heavier than himself with a light horizontal rope. coefficient of friction is sa

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4-2.Friction

hard

A man pulls a block heavier than himself with a light horizontal rope. The coefficient of friction is the same between the man and the ground, and between the block and the ground

AThe block will not move unless the man also moves

BThe man can move even when the block is stationary

CIf both move, the acceleration of the man is greater than the acceleration of the block

DAll of the above

Solution

Let $T=$ tension in rope. Force $T$ acts on both. The limiting force of friction is larger for the block than for the man. each body will move when $T$ exceeds the force of friction. limiting friction on man $<$ limiting friction on block
hence when $T$ exceeds limiting friction of man then man will start moving but block can't
but if $T$ exceeds the limiting friction of block then block will also start moving but with acceleration less than man
thus,
Option $\mathrm{A}, \mathrm{B}, \mathrm{C}$ are correct

Standard 11

Physics

An object of mass $1 \,kg$ moving on a horizontal surface with initial velocity $8 \,m / s$ comes to rest after $10 \,s$. If one wants to keep the object moving on the same surface with velocity $8 \,m / s$ the force required is …… $N$

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A fireman of mass $60\, kg$ slides down a pole. He is pressing the pole with a force of $600 \,N$. The coefficient of friction between the hands and the pole is $0.5$, with what acceleration will the fireman slide down …….. $m/s^2$

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$Assertion$ : On a rainy day it is difficult to drive a car or bus at high speed.
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(AIIMS-1999)

A heavy box of mass $50 \mathrm{~kg}$ is moving on a horizontal surface. If co-efficient of kinetic friction between the box and horizontal surface is $0.3$ then force of kinetic friction is :

easy

(JEE MAIN-2024)

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medium

(JEE MAIN-2013)

A man pulls a block heavier than himself with a light horizontal rope. The coefficient of friction is the same between the man and the ground, and between the block and the ground

Solution

Similar Questions

An object of mass $1 \,kg$ moving on a horizontal surface with initial velocity $8 \,m / s$ comes to rest after $10 \,s$. If one wants to keep the object moving on the same surface with velocity $8 \,m / s$ the force required is …… $N$

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$Assertion$ : On a rainy day it is difficult to drive a car or bus at high speed.
$Reason$ : The value of coefficient of friction is lowered due to wetting of the surface