8.7AB Review

A sledgehammer has a mass of 3.5 kilograms. What net force, to the nearest whole newton, will a person need to apply to accelerate the sledgehammer at a rate of 4.0 m/s²?

• 12 N

• 14 N

• 16 N

• 18 N

Which rocket had the greatest acceleration?

• Rocket 1

• Rocket 2

• Rocket 3

• Rocket 4

A student pushes a 51.5 kilogram bookshelf across a smooth floor with a net force of 67 N. What is the approximate acceleration of the bookshelf?

• 1.3 m/s²

• 3,450.5 m/s²

• 15.5 m/s²

• 0.77 m/s²

The diagram shows a duck swimming in a stream in the opposite direction the stream is flowing. The duck pushes against the water, so the water pushes the duck forward with 20 newtons of force. The water also exerts 15 newtons of resistive force against the duck. Which statement best describes the resulting motion of the duck?

• The duck will stop moving.

• The duck will stop and then start moving again.

• The duck will continue moving in its current direction.

• The duck will move in the direction that the stream is flowing.

Immediately after they push away from each other, how does the motion of the mother and daughter change?

• The mother moves forward, and the daughter moves backward with a greater acceleration.

• Both move forward, but the mother moves with a greater acceleration.

• The mother moves backward, and the daughter moves forward with a greater acceleration.

• Both move backward, but the daughter moves with a greater acceleration.

The diagrams show forces acting on a toy car as it moves to the right. Which diagram shows the toy car that will most likely accelerate to the right based on these conditions?

• F

• G

• H

• J

A student bounces a basketball off the gym floor. Which statement correctly describes the action-reaction force pair that causes the ball to bounce?

• The gym floor pushes up on the ball as the ball pushes down on the floor with an equal amount of force.

• The gym floor pushes up on the ball with a greater amount of force than the ball pushes down on the floor.

• The gym floor pushes up on the ball as gravity pulls down on the ball with an equal amount of force.

• The gym floor pushes up on the ball with a greater amount of force than gravity pulls down on the ball.

Based on the data table, which cart has the lowest acceleration?

• W

• X

• Y

• Z

A plastic tube is arranged on a lab tabletop as shown. A small sphere enters one end of the tube with enough speed to come out the other end of the tube. Which diagram shows where the sphere will go first when it leaves the tube?

• A

• B

• C

• D

A photograph of a bird perched on a fence post is shown. Which description best identifies the action-reaction pair between the bird and the fence post?

• Action: The force of the bird on the wires, Reaction: The force of the wires on the fence post.

• Action: The force of the wires on the fence post, Reaction: The force of the fence post on the bird.

• Action: The force of the fence post on the bird, Reaction: The force of the bird on the wires.

• Action: The force of the bird on the fence post, Reaction: The force of the fence post on the bird.