Newton's Laws of Motion

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

Tags

112.20.b.6.C

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?

• The force of gravity causes the coin to change its velocity

• The coin's inertia decreases on the way up and increases on the way down

• The action-reaction force pair of gravity and the applied force cancel each other

• The coin remains in its state of upward motion until the force of friction acts upon it

Tags

112.20.b.6.C

According to Newton's first law, what happens to the steel ball just after the box stops?

• Because of friction, the ball continues rolling forward at the same speed

• Because of friction, the ball rolls forward at an increased speed

• Because of inertia, the ball continues rolling forward at the same speed

• Because of inertia, the ball rolls forward at an increased speed

Tags

112.20.b.6.C

Which statement best describes an action-reaction force pair in this situation?

• The wall pushes on the skater when the skater pushes on the wall

• The wheels slow down, and the skater stops

• The skater exerts a force on the wall, and the wheels exert a force on the floor and begin to turn

• The friction of the floor decreases when the wheels roll on the floor

Tags

112.20.b.6.C

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

• There are no forces acting on the rock

• The only force acting on the rock is directed toward the sidewalk

• The forces acting on the rock are all balanced

• The sidewalk exerts an unbalanced force on the rock

Tags

112.20.b.6.C

A pitcher throws a ball toward a player holding a softball bat. The player uses the bat to hit the ball. The bat applies a 10-newton force to the ball.

Which statement correctly describes the reaction force between the bat and ball?

• The reaction force is the force that causes the ball to move toward the bat

• The reaction force is the force applied to the bat by the player holding the bat

• The reaction force is the force that pulls the ball toward the ground

• The reaction force is the force of the ball on the bat

Tags

112.20.b.6.C

An action-reaction pair of forces exists between -

• the aerialist's feet and the rope

• the rope and the balancing bar

• the two ends of the rope

• the aerialist's arms and legs

Tags

112.20.b.6.C

Four boxes are sliding with constant speed before each box experiences an unbalanced force of 8 N. Which box would experience the greatest acceleration when the unbalanced force is applied?

• The box with a mass of 2 kg

• The box with a mass of 4 kg

• The box with a mass of 6 kg

• The box with a mass of 8 kg

Tags

112.20.b.6.C

If the load exerts a strong downward force, the glue -

• destroys the force

• exerts a stronger downward force

• causes the load to accelerate upward

• exerts an upward force that is equal to the downward force

Tags

112.20.b.6.C

Which statement best describes the acceleration of the box?

• The box accelerates at 1.0 m/s² to the right because the net force is 17 N to the right

• The box accelerates at 1.9 m/s² to the right because the great force is to the right

• The box accelerates at 3.0 m/s² because the combined forces cause the box to accelerate

• The box does not accelerate, because neither force is large enough to move the box

Tags

112.20.b.6.C