Friction

Friction is a force that acts in an ___________ direction of movement.

• similar
• opposite
• parallel
• west

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

• True
• False

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

• Brakes used on a bike
• Tires from a car on the road
• Tread on the bottom of your shoes
• All are examples that are helpful

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

• Pencil marking on paper
• Engine parts wearing out
• sand placed on ice in the winter
• Using an eraser to erase marks

Rougher surfaces have ...

• greater friction
• less friction
• the same level of friction