Unit 5: Forces & Motion Study Guide Review

Two football players are running toward each other. One football player has a mass of 100 kg and is running at 8 m/s. The other player has a mass of 90 kg and is running at -9 m/s.

What is the momentum of the system after the football players collide?

• 190 kg * m/s

• 10 kg * m/s

• 90 kg * m/s

• 180 kg * m/s

Explain why a semi truck would have a harder time stopping while speeding down a hill than a car would at the same speed.

A bicycle has a momentum of 64 kg • m/s and a velocity of 8 m/s. What is the mass of the bicycle?

• 4 kg

• 56 kg

• 8 kg

• 72 kg

The graph shows two runners participating in a race.

Which best describes the runners?

• Daniela had a 5 meter head start, and Leonard caught up to her at 25 meters.

• Daniela ran faster than Leonard through the entire race.

• Daniela gave Leonard a 5 meter head start and caught up to him at 25 meters.

• Daniela ran slower than Leonard, but she went faster at the end.

A toy car is placed at 0 on a number line. It moves 4 cm to the left, then 6 cm to the right, and then 3 cm to the left. What is the total distance the toy car traveled?

• 1

• -1

• 13

• -13

Olivia places her pet frog on a line to observe the frog’s motion. The line is divided into sections that measure 1 centimeter each. The frog begins at 0, moves 2 centimeters forward, moves 6 centimeters backward, 12 centimeters forward, and then 3 centimeters backward. What is the frog's total displacement?

• 3

• -9

• -2

• 5

Which graph best represents a car that is accelerating?

• A

• B

• C

• D

What is the acceleration of a 20 kg object pushed with a force of 400 newtons?

• 80

• 8000

• 20

• 200

Which force is always present and pulls downward on objects?

• normal force

• gravity

• push/pull force

• friction

If a car has a speed of 20 mph and maintains that same speed while turning left, it has changed what?

• force

• momentum

• speed

• velocity