Forces and Motion

In a rubber duck race, the winning duck traveled 300 meters in 10 minutes. What was the duck’s average speed?

• 0.5 m/s

• 1.0 m/s

• 7.5 m/s

• 30 m/s

If a small rock and a large rock are both thrown at a wall at exactly the same speed, which rock would most likely cause more damage to the wall?

• The large rock would cause more damage because the force would be spread out on a larger area.

• The large rock would cause more damage because it has a greater mass, making the momentum greater.

• The small rock would cause more damage because it has a smaller mass, making the momentum greater.

• The small rock would cause more damage because all of the force would be concentrated on one small area.

Michelle drove 300 miles in 6 hours. What was Michelle’s speed?

(speed = distance ÷ time)

• 30 miles per hour

• 50 miles per hour

• 60 miles per hour

• 80 miles per hour

A book is lying on the dashboard of a car, which is stopped at a red light. Which is the most likely reason for the book to slide backward as the car begins to move forward?

• The book has inertia.

• The book has momentum.

• The book has acceleration.

Carli is trying to determine if a force can change the direction of an object’s motion. The answer to which question will best help her come to a conclusion?

• What happens when a ball rolls down a hill?

• What happens when a bat is used to hit a ball?

• What happens when a moving wagon comes to a stop?

• What happens when a person pushes on a large brick wall?

A student is pushing a box of books across the floor. The student stops, removes some of the books, and then continues pushing the box across the floor. Which best explains how removing some of the books affected the motion of the object?

• Removing some of the books reduced the mass of the box, and less force was needed to push it across the floor.

• Removing some of the books reduced the mass of the box, and more force was needed to push it across the floor.

• Removing some of the books did not affect the amount of force needed to push it across the floor.

• Removing some of the books decreased the mass of the box, and the same amount of force was needed to push it across the floor.

A runner traveled 6 miles in one hour. During the next hour, she traveled 8 miles. Which best describes the motion of the runner during the second hour?

• speeding up

• slowing down

• changing direction

• remaining the same

Four solid balls, each with a different mass, are moving at the same speed. Which ball would require the most force to stop its motion?

• ball with a mass of 5g

• ball with a mass of 10g

• ball with a mass of 15g

• ball with a mass of 20g

Tamara and Justin are racing on the playground. Tamara runs the distance from the basketball goal to the jungle gym in 45 seconds, while Justin runs the same distance in 52 seconds. Which best describes the movement of the students?

• The students ran in different directions.

• Both students ran at the same speed.

• Tamara ran faster than Justin.

• Justin ran faster than Tamara.

Which is true when equal and opposite forces are applied to an object?

• The forces combine.

• There is forward movement.

• There is no change in motion.

• The speed of the object increases.