Friction and Gravity Review

What is the force that opposes motion between two surfaces that are in contact with each other?

• gravity

• friction

• electrical

• magnetic

Which of the following results in a decrease of friction?

• adding sand to an icy sidewalk

• using snow tires

• applying more force when scrubbing a pot

• adding a lubricant to a car engine

What two factors affect the force of gravity?

• mass and volume

• mass and distance

• volume and distance

• gravity is always the same

Your book sitting on a desk experiences what type of friction?

• static friction

• sliding friction

• rolling friction

• fluid friction

What type of friction do falling objects experience?

• static friction

• rolling friction

• sliding friction

• fluid friction

What type of friction do cars experience driving down the road?

• static friction

• sliding friction

• rolling friction

• fluid friction

At what rate do objects accelerate to Earth assuming no air resistance (in a vacuum)?

• objects don't accelerate

• the rate of acceleration depends on the object

• 9.8 m/s

• 9.8 m/s²

Wat is the difference between mass and weight?

• there is no difference

• mass depends on gravity

• weight depends on gravity

• weight depends on friction

When the only force acting on an object is gravity, the object ___________________.

• is in free fall

• is at terminal velocity

• is falling quickly

• should use a parachute

When the upward force of air resistance equals the downward force of gravity, the object is _____________.

• in free fall

• at terminal velocity

• speeding up

• should use a parachute