Friction quiz #2

Which of the following shows the presence of friction?

• cars can continually roll down hills

• people stay in place as they move

• things fall on smooth surfaces

• cars stop when the driver steps on the brakes

It is a force that opposes motion between two surfaces sticking or touching together.

• gravity

• friction

• electrical

• magnetic

It is defined as a push or pull that starts, stops, or changes the direction of a moving object.

• motion

• energy

• force

• food

Which has the greatest frictional force among these surfaces?

• polished floor

• wet floor

• tiled floor

• sandy floor

__________ is a force that opposes motion. It acts in the opposite direction of a moving object.

Which of the following statements best describes friction?

• It is a force that occurs when surfaces touch each other

• it is a force that occurs between solid and liquids

• it is a force that occurs in smooth surfaces

• it is a force that occurs only on rough surfaces

Rougher surfaces have....

• greater friction

• the same level of friction

• less friction

• all these are correct

Which of the following is an example of friction that is helpful?

• brakes used on a bike

• thread on the bottom of your shoes

• tires from a car on the road

• all examples are helpful

Which of this is an example of undesirable effect of friction?

• keeping our balance

• running on the street

• forest fire

• writing in notebook

How can friction be reduced?

• reduce the force acting between the two surfaces

• use wax, grease or oil

• reduce the roughness of the two surfaces coming in contact

• all of these are ways of reducing friction