Kinds of Friction

Static friction prevents you from slipping when you walk on a sidewalk.

• True

• False

A force that opposes motion between any surfaces that are in contact.

• gravity

• acceleration

• friction

• direction

Which type of friction is shown in the picture?

• rolling

• fluid

• static

• sliding

Types of friction include

• static friction.

• sliding friction.

• rolling friction

• all of the above

You can move heavy boxes by sliding them over the ground, or you can put them on a dolly and then roll them over the ground. Which way makes it easier to move the boxes? Why?

• Sliding the boxes on the floor is easier than using the dolly because rolling friction is less than sliding friction

• Sliding the boxes on the floor is easier than using the dolly because sliding friction is less than rolling friction.

• Rolling the boxes over the floor on the dolly is easier because sliding friction is less than rolling friction.

• Rolling the boxes over the floor on the dolly is easier because rolling friction is less than sliding friction.

You use _____ friction when you leave marks on paper with a pencil “lead.”

• static friction.

• sliding friction.

• rolling friction.

Sliding friction is stronger than static friction.

• TRUE

• FALSE

The weakest type of friction that occurs between solid surfaces is _____ friction.

• sliding friction

• rolling friction

• static friction

• None of the above

When you put on the brakes of your bike, the wheels stop turning. Then friction between the wheels and the road slows your bike to a stop. Which type of friction is this?

• static friction.

• sliding friction.

• rolling friction.

• all of the above

The friction force acts in the ...................... direction of movement

• Same

• Opposite

• sometime Opposite