Friction: Types, Coefficients, and Impact on Motion

Question 1

Which of the following surfaces is generally expected to have the highest coefficient of friction?

Accepted Answer

Concrete

Answer

Ice

Answer

Rubber

Answer

Teflon

Question 2

Which of the following is an example of rolling friction in everyday life?

Accepted Answer

Pushing a shopping cart

Answer

Sliding a book across a table

Answer

Dragging a heavy bag on the ground

Answer

Typing on a keyboard

Question 3

Friction is considered a non-conservative force primarily because it:

Accepted Answer

Changes the total energy of the system

Answer

Always acts in the direction of motion

Answer

Depends on the velocity of the object

Answer

Is a contact force

Question 4

Which of the following devices heavily relies on friction to function effectively?

Accepted Answer

Brake pads

Answer

Electric motor

Answer

Wind turbine

Answer

Solar cell

Question 5

In the context of a car traveling at a constant speed on a level road, which force primarily counteracts the frictional force acting on the car?

Accepted Answer

Engine force

Answer

Gravitational force

Answer

Normal force

Answer

Air resistance

Question 6

Which of the following best describes friction?

Accepted Answer

A force that resists the movement of two objects in contact

Answer

A force that always acts in the same direction as the motion of an object

Answer

A force that only occurs between two solid surfaces

Answer

A force that is always harmful to objects

Question 7

Static friction is the force that comes into play when an object:

Accepted Answer

Is at rest

Answer

Is in motion

Answer

Is accelerating

Answer

Is slowing down

Question 8

What is the SI unit for coefficient of friction?

Accepted Answer

Dimensionless

Answer

Newton

Answer

Meter

Answer

Kilogram

Question 9

Friction is always a force that:

Accepted Answer

Opposes relative motion

Answer

Assists motion

Answer

Is perpendicular to motion

Answer

Is parallel to motion

Question 10

Which of the following is NOT a recognized type of friction?

Accepted Answer

Sliding friction

Answer

Static friction

Answer

Kinetic friction

Answer

Rolling friction

Question 11

What is the relationship between the coefficient of static friction (μs) and the angle of repose (θ)?

Accepted Answer

μs = tan θ

Answer

μs > tan θ

Answer

μs < tan θ

Answer

They are unrelated

Question 12

A heavy block is pushed across a rough surface at a constant velocity. Which of the following statements is correct?

Accepted Answer

The force of kinetic friction is equal to the force applied

Answer

The force of static friction is greater than the force applied

Answer

The force of friction is always greater than the force applied

Answer

The force of friction is always less than the force applied

Question 13

A coefficient of kinetic friction of 0.2 implies that:

Accepted Answer

The force of kinetic friction is 20% of the normal force

Answer

The force of kinetic friction is twice the normal force

Answer

The force of kinetic friction is 50% of the normal force

Answer

The force of kinetic friction is 80% of the normal force

Question 14

What is the purpose of applying sand or salt to icy roads?

Accepted Answer

To increase friction

Answer

To decrease friction

Answer

To prevent freezing

Answer

To absorb moisture

Question 15

Which of the following is a dimensionless quantity?

Accepted Answer

Coefficient of friction

Answer

Force

Answer

Velocity

Answer

Acceleration

Question 16

A block is resting on a rough inclined plane. If the angle of inclination is gradually increased, what happens to the force of static friction?

Accepted Answer

It increases until the block starts to slide

Answer

It decreases until the block starts to slide

Answer

It remains constant

Answer

It becomes zero

Question 17

Which statement about kinetic friction is correct?

Accepted Answer

It is directly proportional to the coefficient of kinetic friction

Answer

It is independent of the normal force

Answer

It is always less than static friction

Answer

It is zero when the object is at rest

Question 18

Which of the following surfaces would have the lowest coefficient of friction?

Accepted Answer

Ice and metal

Answer

Concrete and rubber

Answer

Wood and wood

Answer

Sandpaper and metal

Question 19

The coefficient of friction between two surfaces is a measure of:

Accepted Answer

The ratio of the force of friction to the normal force

Answer

The amount of force required to overcome friction

Answer

The roughness of the surfaces

Answer

The type of material used for the surfaces

Question 20

Which of the following types of friction occurs when two surfaces slide past each other?

Accepted Answer

Sliding friction

Answer

Static friction

Answer

Kinetic friction

Answer

Rolling friction

Question 21

A block is resting on a horizontal surface. The frictional force acting on the block is:

Accepted Answer

Zero

Answer

Equal to the force of gravity acting on the block

Answer

Equal to the normal force acting on the block

Answer

Always greater than the force of gravity acting on the block

Question 22

Which factor does NOT affect the coefficient of friction?

Accepted Answer

The velocity of the moving object

Answer

The nature of the surfaces in contact

Answer

The area of contact

Answer

The temperature

Question 23

A car is traveling at a constant speed on a level road. The force of friction acting on the car is:

Accepted Answer

Zero

Answer

Equal to the force of gravity acting on the car

Answer

Equal to the force of the engine acting on the car

Answer

Opposite in direction to the force of the engine acting on the car

Question 24

Which of the following is NOT a benefit of friction?

Accepted Answer

It increases the efficiency of machines

Answer

It enables walking

Answer

It aids in controlling object movement

Answer

It prevents objects from sliding off surfaces

Question 25

A car is traveling on a wet road. The coefficient of friction between the tires and the road is 0.4. The maximum speed at which the car can safely travel without skidding is:

Accepted Answer

v = √(μg)

Answer

v = √(μg/2)

Answer

v = √(g/μ)

Answer

v = √(2μg)

Question 26

The coefficient of friction is a dimensionless quantity that represents:

Accepted Answer

The ratio of the frictional force to the normal force

Answer

The ratio of the normal force to the frictional force

Answer

The angle at which an object slides down an inclined plane

Answer

The time it takes for an object to come to rest

Question 27

Static friction is the force that:

Accepted Answer

Keeps an object at rest on a surface

Answer

Opposes the motion of an object

Answer

Causes an object to move faster

Answer

Is always less than kinetic friction

Question 28

Kinetic friction is the force that:

Accepted Answer

Opposes the motion of an object

Answer

Keeps an object at rest on a surface

Answer

Causes an object to move faster

Answer

Is always greater than static friction

Question 29

Friction is a force that is always:

Accepted Answer

In the opposite direction of the motion of the object

Answer

In the same direction as the motion of the object

Answer

Perpendicular to the motion of the object

Answer

Zero

Question 30

Friction is a force that:

Accepted Answer

Can be both helpful and harmful

Answer

Is always helpful

Answer

Is always harmful

Answer

Only occurs between two solid surfaces

Question 31

Which of the following is NOT a type of friction encountered in everyday life?

Accepted Answer

Frictional torque

Answer

Static friction

Answer

Kinetic friction

Answer

Rolling friction

Question 32

The coefficient of friction is a measure of the:

Accepted Answer

Ratio of the force of friction to the normal force

Answer

Force required to overcome static friction

Answer

Force required to overcome kinetic friction

Answer

Angle at which an object slides down an inclined plane

Question 33

Static friction is the force that:

Accepted Answer

Opposes the motion of an object when it is not moving

Answer

Opposes the motion of an object when it is moving

Answer

Causes an object to roll

Answer

Causes an object to slide

Question 34

Kinetic friction is the force that:

Accepted Answer

Opposes the motion of an object when it is moving

Answer

Opposes the motion of an object when it is not moving

Answer

Causes an object to roll

Answer

Causes an object to slide

Question 35

The force of friction is always:

Accepted Answer

Parallel to the surface of contact

Answer

Perpendicular to the surface of contact

Answer

At an angle to the surface of contact

Answer

Independent of the surface of contact

Question 36

Which of the following factors does NOT affect the coefficient of friction between two surfaces?

Accepted Answer

The velocity of the object

Answer

The nature of the surfaces in contact

Answer

The normal force

Answer

The temperature

Question 37

Friction is a force that:

Accepted Answer

Can oppose or assist motion

Answer

Always opposes motion

Answer

Always assists motion

Answer

Has no effect on motion

Question 38

The coefficient of friction between two surfaces can vary depending on the conditions?

Accepted Answer

True

Answer

False

Question 39

Which of the following is NOT a factor that influences the coefficient of static friction?

Accepted Answer

Temperature

Answer

Surface roughness

Answer

Normal force

Answer

Material composition

Question 40

An object on a flat surface with a kinetic friction coefficient of 0.2 is subjected to a 100 N parallel force. What is the resulting friction force?

Accepted Answer

20 N

Answer

50 N

Answer

100 N

Answer

None of these

Question 41

Which type of friction occurs when surfaces are in contact, with at least one moving?

Accepted Answer

Kinetic friction

Answer

Static friction

Answer

Rolling friction

Answer

Fluid friction

Question 42

A 10 kg block is placed on a flat surface with a friction coefficient of 0.4. Calculate the maximum force applicable to the block without causing movement.

Accepted Answer

40 N

Answer

10 N

Answer

100 N

Answer

400 N

Question 43

Which of the following does NOT affect the magnitude of friction?

Accepted Answer

Temperature

Answer

Normal force

Answer

Coefficient of friction

Answer

Surface roughness

Question 44

Which of the following is an example of static friction in action?

Accepted Answer

A book resting on a table

Answer

A ball rolling down a hill

Answer

A car skidding on ice

Answer

A person walking on a sidewalk

Question 45

The coefficient of friction is:

Accepted Answer

A dimensionless quantity

Answer

Dependent on the force of gravity

Answer

Always greater than 1

Answer

Measured in Newtons

Question 46

What is the SI unit of friction?

Accepted Answer

Newton

Answer

Pascal

Answer

Joule

Answer

Watt

Question 47

Which of the following statements about friction is correct?

Accepted Answer

Friction is a non-conservative force

Answer

Friction is always beneficial

Answer

Friction is the only force that opposes motion

Answer

Friction can be neglected in most real-world scenarios

Question 48

A wooden block rests on a horizontal surface. Which force prevents the block from moving?

Accepted Answer

Static friction

Answer

Air resistance

Answer

Normal force

Answer

Gravity

Question 49

What type of friction acts on a sliding box?

Accepted Answer

Kinetic friction

Answer

Static friction

Answer

Fluid friction

Answer

Rolling friction

Question 50

The coefficient of friction between two surfaces indicates:

Accepted Answer

The relative roughness of the surfaces

Answer

The distance over which friction acts

Answer

The amount of force needed to overcome friction

Answer

The normal force between the surfaces

Question 51

A heavier object on a surface experiences:

Accepted Answer

A greater normal force, resulting in a greater frictional force.

Answer

No frictional force

Answer

The same frictional force as a lighter object

Answer

A smaller frictional force

Question 52

Which factor does NOT affect the magnitude of friction?

Accepted Answer

The color of the surfaces

Answer

The normal force between the surfaces

Answer

The area of contact between the surfaces

Answer

The type of surfaces

Question 53

A constant-speed car on a level road has forces acting on it such that:

Accepted Answer

The force of friction equals the force of the engine.

Answer

The force of friction is greater than the force of the engine.

Answer

The force of friction is less than the force of the engine.

Question 54

Which scenario would result in the highest kinetic friction?

Accepted Answer

A heavy box sliding on a rough concrete floor.

Answer

A light box rolling on a rough concrete floor.

Answer

A heavy box rolling on a smooth wooden floor.

Answer

A light box sliding on a smooth wooden floor.

Question 55

What primarily slows down and stops a ball thrown horizontally across a room?

Accepted Answer

Air resistance

Answer

Rolling friction

Answer

Gravity

Answer

Static friction