FRICTION

Multiple Choice

Which of the following is an advantage of friction?

• It causes wear and tear on machines

• It helps us walk without slipping

• It makes moving objects harder

• It increases fuel consumption

​RELATIVE MOTION

Multiple Choice

Which of the following best defines friction?

• A force that opposes motion between surfaces in contact

• A force that attracts objects to each other

• A force that only acts in liquids

• A force that increases motion between surfaces

Fill in the Blanks

Friction is maximum in case of

and least in case of gases.

Open Ended

Explain why friction is considered a contact force and give examples of where it is maximum and minimum.

Multiple Choice

What causes friction between two solid surfaces?

• Interlocking of ridges and grooves

• Smoothness of surfaces

• Absence of contact

• Presence of water

Open Ended

Describe how the roughness of a surface influences the amount of friction experienced when riding a bicycle on different terrains.

Multiple Select

Which of the following factors affect friction?

• Nature of the surface

• Weight (normal force)

• Surface in contact

• Temperature

Multiple Choice

Which of the following is NOT a type of friction?

• Static friction

• Magnetic friction

• Rolling friction

• Fluid friction

Fill in the Blanks

Friction between two solid objects that are not moving relative to each other is called

friction.

Multiple Choice

Sliding friction is also known as:

• Static friction

• Kinetic friction

• Rolling friction

• Fluid friction

Open Ended

Explain how rolling friction is different from sliding friction, using examples from daily life.

Multiple Select

Which of the following are examples of fluid friction?

• A swimmer moving through water

• A car's wheels rolling on the ground

• An airplane flying through air

• A box being pushed across the floor

Multiple Choice

Which factor does NOT increase drag on an object moving through a fluid?

• Increasing the speed of the object

• Making the fluid denser

• Decreasing the surface area of the object

• Making the object rougher

Multiple Choice

Arrange the following types of friction in order from strongest to weakest: Sliding friction, Rolling friction, Static friction.

• Static friction > Sliding friction > Rolling friction

• Sliding friction > Static friction > Rolling friction

• Rolling friction > Sliding friction > Static friction

• Sliding friction > Rolling friction > Static friction

Fill in the Blanks

Fill in the blank: Friction is responsible for the wear and tear on bike gears and other mechanical

.

Open Ended

Explain two ways in which friction is useful in our daily lives, based on the applications mentioned.

Multiple Select

Which of the following are consequences of low friction as described in the slides?

• It becomes difficult to walk on slippery roads

• Nails cannot be fixed in wood or wall

• Machines produce more heat

• A horse cannot pull a cart without secure foothold

Multiple Choice

Which of the following is NOT a disadvantage of friction according to the slides?

• It produces heat in machines

• It helps in writing on a board

• It causes wear and tear of shoes

• It increases fuel consumption in engines

Open Ended

Describe how lubricants help in reducing friction in machines, as shown in the slides.

Multiple Choice

Which method is used in machines to replace sliding friction with rolling friction?

• Using lubricants

• Using ball bearings

• Changing the shape of objects

• Increasing weight

Open Ended

Explain how the design modification of vehicles and airplanes helps to reduce friction.

Fill in the Blanks

A streamlined body helps to reduce the friction between a fluid and an object moving through that fluid. Fill in the blank: A streamlined body is designed to minimize

resistance.

Open Ended

Summarize the different types of friction and give one example of each.

Multiple Select

Which of the following are methods to reduce friction?

• Use of lubricants

• Use of ball bearings

• Increasing surface roughness

• Streamlined body

Multiple Choice

Which of the following is NOT a learning outcome for the chapter on friction?

• Explain the terms friction and drag.

• List advantages and disadvantages of friction.

• Describe the process of photosynthesis.

• Differentiate between static friction and sliding friction.

Open Ended

Reflecting on what you have learned about friction and drag, what is one real-life situation where understanding friction is important?