AP Intro to Friction

The force of friction always acts which direction?

• In the direction you are moving/are trying to be moving

• Opposite of the direction you are moving/trying to be moving

• Always in the same direction as the force of gravity

• It depends on the situation

Is there friction?? An object is sitting on a flat surface with nothing pushing it.

• Yes!

• No!

• It depends on the mass

Is there friction??? A block is sitting on an inclined ramp, not moving. Nobody is touching the block.

• Yes!

• No!

• It depends on mass.

Tags

NGSS.HS-PS2-1

Select the true statements.

• Kinetic friction is when something is moving

• Kinetic friction is when something is not moving

• Static friction is when something is moving

• Static friction is when something is not moving

What does the coefficient of friction describe?

• How heavy two objects rubbing together are

• How fast two objects are rubbing together

• How rough or smooth two surfaces are rubbing together

• How much inertia two objects rubbing together have

I am pushing a refrigerator really hard to the right. It is not yet moving. Select the true statement.

• Since it is not moving, there is no friction on the refrigerator.

• There is static friction going to the left the same size that I am pushing

• There is static friction going to the left harder than I am pushing

• There is kinetic friction going to the left the same size that I am pushing

Tags

NGSS.HS-PS2-1

I push a refrigerator really really hard to the right. It starts to slide. What is true?

• There is no friction since I pushed hard enough to make it slide.

• There is kinetic friction opposing motion, pointing to the left.

• There is kinetic friction going to the right.

• There is static friction opposing motion, pointing to the left.

Tags

NGSS.HS-PS2-1

Mr. Vause throws Mr. Wister down the hallway to the right, and Wister starts to slide. Mr. Vause is no longer touching Mr. Wister. Which describes his motion? There is friction.

• Because of Newton's First Law, Wister will move forever until he hits into the wall

• Wister is sliding to the right, friction is to the left, and Wister is accelerating to the right

• Wister is moving to the right, friction is to the left, and Wister is moving at a constant velocity

• Wister is moving to the right, friction is to the left, and Wister is accelerating to the left

Tags

NGSS.HS-PS2-1