Physical Science forces review

Which of the following statements is true regarding friction?

• Friction always opposes motion

• Friction sometimes opposes motion

• Friction always causes motion

• Friction always acts in the same direction as motion

The amount of friction between two surfaces depends on which factor?

• electric charge

• type of surfaces

• magnetism

• gravity

Which of the following is an example of static friction?

• Sliding a box across the carpet

• Pushing a heavy object across the floor

• Rolling a ball across a table

• A book sitting on a table

When sledding down a hill, what could you do to decrease friction?

• Increase the weight on the sled

• Decrease the weight on the sled

• Attach sandpaper to the bottom of the sled

• Make sure the bottom of the sled is dry

What type of friction occurs when an object moves through air or water?

• fluid

• rolling

• static

• sliding

How does friction affect speed?

• more friction decreases speed

• less friction decreases speed

• more friction increases speed

• less friction doesn’t affect speed

You observe a book resting on a table. What kind of friction are you observing?

• Sliding friction

• Rolling friction

• Air resistance

• Static friction

What type of force resists motion between surfaces in contact with one another?

• friction

• gravity

• electrical

• magnetic

A boy is rolling a rubber ball on a wooden surface and it doesn't go very far. What can he do to make the ball roll further?

• spread a carpet on the wooden surface.

• cover the ball with a piece of cloth.

• sprinkle talcum powder on the wooden surface.

• sprinkle sand on the wooden surface.

A ball bearing is a small metal ball (or several of these) arranged in a ring to make particular parts of a machine move more easily. Ball bearings in a wheel are an example of friction.

• static friction

• kinetic friction

• rolling friction
• fluid friction