Copy of Science 8.6C

1.

2.

• 
• 
• 
• 

3. A researcher observes a car speeding up from rest. The researcher records data about the car and the car's motion. Which data points can be used to calculate the net force that was acting on the car when it was speeding up? Select TWO correct answers

• The car's mass is 1,000 kg.
• The car's speed increased for 7 seconds.
• The car started from rest.
• The car's acceleration was 4 meters per second squared.
• The car traveled a total of 300 m.

4. This question has two parts. A player hits a baseball with a baseball bat. Part A Which statement about the forces between the ball and the bat is correct?

• A The force of the ball on the bat was less than the force of the bat on the ball.
• B The force of the ball on the bat was equal to the force of the bat on the ball.
• C The force of the ball on the bat was greater than the force of the bat on the ball.

4. Part B Which statement BEST supports the answer to Part A?

• A Whenever two objects interact, the more massive object always applies a greater force than the less massive object.
• B Whenever two objects interact, the faster object always applies a greater force than the slower object.
• C Whenever two objects interact, they always apply equal and opposite forces on each other.
• D Whenever two objects interact, their forces always combine and are applied in the direction of the object that is moving the fastest.

5.

• A Action: The force of the bird on the wires Reaction: The force of the wires on the fence post
• B Action: The force of the wires on the wires Reaction: The force of the bird on the fence post
• C Action: The force of the fence post on the bird Reaction: The force of the bird on the wires
• D Action: The force of the bird on the fence post Reaction: The force of the fence post on the bird

6. When a coin is tossed in the air, it travels upward, gradually slows down, momentarily reaches zero speed, then moves back downward with increasing speed. Which statement best explains this change in the coin's motion?

• F The force of gravity causes the coin to change its velocity.
• G The coin's inertia decreases on the way up and increases on the way down.
• H The action-reaction force pair of gravity and the applied force cancel each other.
• J The coin remains in its state of upward motion until the force of friction acts upon it.

7.

• A Because of friction, the ball continues rolling forward at the same speed.
• B Because of friction, the ball rolls forward at an increased speed.
• C Because of inertia, the ball continues rolling forward at the same speed.
• D Because of inertia, the ball rolls forward at an increased speed.

8.

• F The wall pushes on the skater when the skater pushes on the wall.
• G The wheels slow down, and the skater stops.
• H The skater exerts a force on the wall, and the wheels exert a force on the floor and begin to turn.
• J The friction of the floor decreases when the wheels roll on the floor.

9. A large rock is motionless on a flat sidewalk. Which statement best explains why the rock remains motionless?

• A There are no forces acting on the rock.
• B The only force acting on the rock is directed toward the sidewalk.
• C The forces acting on the rock are all balanced.
• D The sidewalk exerts an unbalanced force on the rock.