Force and Motion Practice

How does friction affect speed?

• More friction decreases speed

• More friction increases speed

• Less friction decreases speed

The force necessary to keep planets in orbit around the Sun is…

• Gravity

• Friction

• Magnetism

• Nuclear

Ari had one ball and two ramps. The ramps were identical except that one had a sandpaper surface and one had a plastic surface. Ari measured how long it took the ball to roll down each ramp. Ari MOST likely was investigating the effect of which force on the speed of the ball?

• Electricity

• Friction

• Gravity

• Magnetism

Sometimes machines are used to lower heavy objects from the top of a building to the ground. Which is most responsible for making the object move to the ground?

• Wind

• Gravity

• Friction

• Momentum

Tina washes her hands with a bar of soap. When she gets the soap wet, it becomes very slippery. What force decreases as the soap becomes wet?

• Electricity

• Friction

• Gravity

• Magnetism

When pushed with the same amount of force across a desk, which toy car would most likely travel the fastest?

• A car weighing 25 grams

• A car weighing 20 grams

• A car weighing 15 grams

A ball was rolling fast and then slowed. Which most likely caused the ball to slow?

• Heat

• Wind

• Friction

• Momentum

A plane carrying bags has a mass of 50,000 kg. After delivering the bags, it has a mass of 30,000 kg. Which would best describe how the plane’s motion would be affected on the way back?

• The plane would travel at a faster speed.

• The plane would travel at a slower speed.

• The plane would travel at the same speed.

Why would you need more force when riding a bike up a hill than down a hill?

• The mass of a bicycle is less when riding up a hill.

• The mass of a bicycle is greater when riding up a hill.

• More force is needed to keep a bike going up a hill while gravity is pulling it down the hill.

Which best explains why a ball increases in speed as it rolls down a hill?

• The ball increases in speed because of friction.

• The ball increases in speed because of gravity.

• The ball increases in speed because the mass changes.