Introduction to Newton's Law of Motion Quiz

Ethan is playing with a soccer ball on a smooth field. Which of the following best describes Newton's First Law of Motion?

• The soccer ball will eventually stop due to friction with the grass.

• An object at rest stays at rest, and an object in motion stays in motion unless acted upon by an external force.

• The soccer ball stays in motion only in the presence of a kick.

• The soccer ball will remain still only if a player applies a force.

Answer explanation

Newton's First Law states that an object at rest stays at rest, and an object in motion stays in motion unless acted upon by an external force. This explains why the soccer ball will eventually stop due to friction.

Michael is trying to push a heavy box across the floor, but it doesn't move. Which force is likely preventing its motion?

• Friction

• Gravity

• Upthrust

• Tension

Answer explanation

Friction is the force that opposes the motion of the box across the floor. It acts between the box and the surface, preventing it from moving despite Michael's efforts to push it.

Avery is pushing against a wall in her classroom. According to Newton's Third Law, what happens?

• The wall does not exert any force.

• The wall exerts an equal and opposite force on Avery.

• The wall exerts a greater force on Avery.

• The wall exerts a lesser force on Avery.

Answer explanation

According to Newton's Third Law, for every action, there is an equal and opposite reaction. When Avery pushes against the wall, the wall exerts an equal and opposite force back on her.

Kai is riding his bicycle down a straight road. What will happen to the bicycle if no external forces act on it?

• It will gradually slow down and stop.

• It will continue moving at the same speed in the same direction.

• It will change direction.

• It will accelerate.

Answer explanation

According to Newton's first law of motion, an object in motion stays in motion at a constant velocity unless acted upon by an external force. Therefore, if no external forces act on Kai's bicycle, it will continue moving at the same speed in the same direction.

Which of the following scenarios is an example of Newton’s Second Law of Motion?

• Luna pushes a shopping cart and it accelerates forward.

• Abigail's bicycle remains stationary in the driveway.

• William's backpack sits on the floor without moving.

• A person leans against a wall and the wall pushes back.

Answer explanation

Luna's action of pushing the shopping cart demonstrates Newton's Second Law, which states that force equals mass times acceleration (F=ma). The cart accelerates forward due to the force applied by Luna.

Grace is conducting an experiment with a model rocket. What does Newton's Third Law of Motion imply when her rocket launches into the air?

• The rocket engines exert force on the ground, and the ground pushes the rocket upwards.

• The rocket engines exert force on the exhaust gases, and the gases push the rocket upwards.

• The rocket engines exert force on the air, and the air pushes the rocket upwards.

• The rocket moves due to the absence of gravity in space.

Answer explanation

According to Newton's Third Law, for every action, there is an equal and opposite reaction. The rocket engines push exhaust gases down, and in response, the gases push the rocket upwards, making this the correct choice.

Which of the following is a demonstration of inertia, as described by Newton's First Law?

• Harper's car accelerating when she steps on the gas.

• A ball thrown upwards by William coming back down due to gravity.

• A book sliding off the dashboard when Grace suddenly stops the car.

• A leaf floating in the wind.

Answer explanation

The correct choice, 'A book sliding off the dashboard when Grace suddenly stops the car,' illustrates inertia. The book continues in motion due to its inertia until acted upon by an external force (the sudden stop).

Ava is pushing a shopping cart at the grocery store. If she applies a larger force to the cart, what happens according to Newton’s Second Law of Motion?

• The cart’s mass increases.

• The cart’s acceleration increases.

• The cart’s weight decreases.

• The cart’s velocity decreases.

Answer explanation

According to Newton’s Second Law of Motion, force equals mass times acceleration (F=ma). If Ava applies a larger force to the cart, the acceleration increases, assuming the mass remains constant.

Mia is sitting on a chair and exerts a downward force on it. What is the reaction force from the chair?

• The chair exerts an upward force on Mia.

• The chair exerts a downward force on the ground.

• The chair does not exert any force.

• Mia exerts a backward force.

Answer explanation

According to Newton's third law, for every action, there is an equal and opposite reaction. Mia exerts a downward force on the chair, so the chair exerts an upward force on Mia, which is the correct reaction force.

During a physics class, Olivia observed a ball rolling on the ground and another ball resting on a table. Which of the following is true regarding Newton’s First Law of Motion?

• It only applies to objects in motion.

• It applies to objects at rest and in motion.

• It applies only to objects at rest.

• It doesn’t apply in space.

Answer explanation

Newton's First Law states that an object at rest stays at rest and an object in motion stays in motion unless acted upon by a force. Therefore, it applies to both the ball rolling and the ball at rest.