Force and Friction

How would the absence of friction affect a marble travelling on a long, straight path?

• The marble’s speed would decrease.

• The marble’s speed would increase.

• The marble would stop immediately. 

• The marble would remain at a constant speed.

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What is friction?

• It is a resistance force

• Friction does not exist

• It is an imaginary force

• It is a force that moves objects at a constant speed

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If heavy objects are made to roll, _______friction comes into play.

• sliding friction

• rolling

• static friction

• kinetic friction

Which is not the advantage of friction?

• Friction helps in walking.

• Friction allows us to write on paper.

• Cars and buses move safely on roads due to friction.

• Friction causes wear and tear.

Tyres of vehicles have grooved designs to

• reduce friction

• increase friction

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Friction can be increased by increasing the ________of the surfaces in contact.

• Smoothness

• Area

• Roughness

• None of the above

How can friction be reduced?

• reduce the force acting between the 2 surfaces

• reduce the roughness of the 2 surfaces coming in contact

• use wax, grease or oil

• all of the above are ways of reducing friction

The amount of friction depends on the weight of the objects pressing together.

• True

• False

Rougher surfaces have ...

• greater friction

• less friction

• the same level of friction

• no friction at all

What type of friction is not moving?

• static

• sliding

• fluid

• rolling