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A block is gently placed on a conveyor belt moving horizontally with constant speed. After 4s the velocity of the block becomes equal to the velocity of belt. If the coefficient of friction between the block and the belt is 0.2, then velocity of the conveyor belt is

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Important Questions on Friction

EASY

Physics>Mechanics>Friction>Friction

A block of mass

10 kg

starts sliding on a surface with an initial velocity of

9.8 {ms}^{- 1}

. The coefficient of friction between the surface and block is

0.5

. The distance covered by the block before coming to rest is :[use

g = 9.8 {ms}^{- 2}

]

MEDIUM

Physics>Mechanics>Friction>Friction

A block of mass $m$ slides along a floor while a force of magnitude $F$ is applied to it at an angle $θ$ as shown in figure. The coefficient of kinetic friction is $μ_{K}$ . Then, the block's acceleration $a$ is given by : ( $g$ is acceleration due to gravity)

Question Image

EASY

Physics>Mechanics>Friction>Friction

What is the maximum force

F

that can be applied on block

m_{1},

so that both

m_{1} & m_{2}

will move together? There is no friction between

m_{1}

and the horizontal table. The coefficient of friction between

' m_{1}'

and

' m_{2}'

μ .

EASY

Physics>Mechanics>Friction>Friction

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

and kept in equilibrium 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:

MEDIUM

Physics>Mechanics>Friction>Friction

A car is negotiating a curved road of radius

R

. The road is banked at an angle

θ

. The coefficient of friction between the tyres of the car and the road is

μ_{s}

. The maximum safe velocity on this road is:

EASY

Physics>Mechanics>Friction>Friction

Which of the following is a self adjusting force?

MEDIUM

Physics>Mechanics>Friction>Friction

A solid cylinder of mass $m$ is wrapped with an inextensible light string and, is placed on a rough inclined plane as shown in the figure. The frictional force acting between the cylinder and the inclined plane is:

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[The coefficient of static friction, $μ_{s}$ , is $0.4$ ]

EASY

Physics>Mechanics>Friction>Friction

A block rests on a rough inclined plane making an angle of

30 °

with the horizontal. The coefficient of static friction between the block and the plane is

0.8

. If the frictional force on the block is

10 N

, the mass of the block is

(g = 10 m s^{- 2})

MEDIUM

Physics>Mechanics>Friction>Friction

A uniform chain of length

L

is lying partly on a table, the remaining part hanging down from the edge of the table. If the coefficient of friction between the chain and the table is

0.5,

what is the minimum length of the chain that should lie on the table, to prevent the chain from slipping down to the ground?

EASY

Physics>Mechanics>Friction>Friction

Meena applies the front brakes while riding on her bicycle along a flat road. The force that slows her bicycle is provided by the

EASY

Physics>Mechanics>Friction>Friction

A block A of mass 4 kg is placed on another block B of mass 5 kg, and the block B rests on a smooth horizontal table. If the minimum force that can be applied on A so that both the blocks move together is 12 N, the maximum force that can be applied on B for the blocks to move together will be :

HARD

Physics>Mechanics>Friction>Friction

Put a uniform meter scale horizontally on your extended index fingers with the left one at

0.00 cm

and the right one at

90.00 cm

. When you attempt to move both the fingers slowly towards the center, initially only the left finger slips with respect to the scale and the right finger does not. After some distance, the left finger stops and the right one starts slipping. Then the right finger stops at a distance

x_{R}

from the center

(50.00 cm)

of the scale and the left one starts slipping again. This happens because of the difference in the frictional forces on the two fingers. If the coefficients of static and dynamic friction between the fingers and the scale are

0.40

and

0.32

, respectively, the value of

x_{R}

(in cm) is___________.

EASY

Physics>Mechanics>Friction>Friction

A body of mass

2 kg

is kept by pressing to a vertical wall by a force of

100 N

. The friction between wall and body is

0.3

. Then the frictional force is equal to

EASY

Physics>Mechanics>Friction>Friction

Which one of the following statements is incorrect?

EASY

Physics>Mechanics>Friction>Friction

A block is released from rest on a

45 °

smooth incline and slide a distance

d

. The time taken to slide the same distance is

n

times as much to slide on a

45 °

rough incline than on the smooth incline. The coefficients of friction for the rough incline is

EASY

Physics>Mechanics>Friction>Friction

A thin motorcyclist rides with sufficient speed in the vertical plane inside a hollow sphere of diameter

20 m

to prevent himself from sliding down. If the coefficient of friction is

0.5,

then what is the minimum speed of the motor cyclist? (use

g = 10 m s^{- 2}

)

EASY

Physics>Mechanics>Friction>Friction

A block placed on the horizontal is pushed momentarily with initial velocity

v

. The coefficient of friction between the block and surface is

μ

. Block will come to rest after a time

t

equal to (

g =

acceleration due to gravity)

MEDIUM

Physics>Mechanics>Friction>Friction

An inclined plane is bent in such a way that the vertical cross-section is given by

y = \frac{x^{2}}{4}

, where

y

is in vertical and

x

in horizontal direction. If the upper surface of this curved plane is rough with coefficient of friction

μ = 0.5,

the maximum height in

cm

at which a stationary block will not slip downward is________

cm .

HARD

Physics>Mechanics>Friction>Friction

A block of mass

100 kg

attached to a massless rope and the second end of the rope is pulled up by

2

men along a rough inclined plane of coefficient of friction

0.2

inclined at

37 °

with the horizontal. If they exert their maximum force for the block to just start moving up, the force exerted by each of them is, (Acceleration due to gravity

= 10 m s^{- 2}, \tan 37 ° ≃ 0.75

)

MEDIUM

Physics>Mechanics>Friction>Friction

A block of mass

m

is placed on a surface with a vertical cross section given by

y = \frac{x^{3}}{6}

. If the coefficient of friction is

0.5

, the maximum height above the ground at which the block can be placed without slipping is

A block is gently placed on a conveyor belt moving horizontally with constant speed. After 4s the velocity of the block becomes equal to the velocity of belt. If the coefficient of friction between the block and the belt is 0.2, then velocity of the conveyor belt is

Important Questions on Friction

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