Net Force & Newton's Laws

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 and opposite force.

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

Tags

NGSS.MS-PS2-1

The mass, applied force, and frictional force for four carts are shown in the table. Based on the data table, which cart has the lowest acceleration?

• W

• X

• Y

• Z

Tags

NGSS.MS-PS2-2

Which statement BEST explains the correct answer for the question above.

• The cart will have the lowest acceleration if it has a larger mass and its applied force and friction have the greatest sum.

• The cart will have the lowest acceleration if it has a smaller mass and its applied force and friction have the greatest sum.

• The cart will have the lowest acceleration if it has a larger mass and has the least difference between its applied force and friction.

• The cart will have the lowest acceleration if it has a smaller mass and has the least difference between the applied force and friction.

Tags

NGSS.MS-PS2-2

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.

Tags

NGSS.MS-PS2-2

Which forces directly affect a 1.5-kilogram block's motion both before and after it is released when pushed rapidly?

• Gravity and friction

• Magnetic force and tension

• Air resistance and buoyancy

• Electrostatic force and normal force

Tags

NGSS.MS-PS2-2

NGSS.MS-PS2-4

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

Tags

NGSS.MS-PS2-1

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 out.

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

Tags

NGSS.MS-PS2-2

NGSS.MS-PS2-4

A steel ball is at one end of a box that is moving forward as shown. The box suddenly stops. 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.

A skater pushes off a wall and skates backward for a few meters before stopping. 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

NGSS.MS-PS2-1

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.