Newton’s Third Law of Motion

Newton’s Third Law of Motion is a key concept in physics, encapsulating the intrinsic nature of forces. This law illustrates that forces always occur in pairs and that the interactions of objects result in forces that are equal in magnitude and opposite in direction. Its understanding is vital for comprehending a wide range of physical phenomena, from basic motion to complex engineering principles. The law is not only fundamental in theoretical physics but also has practical applications in technology, sports, and everyday life.

What is Newton’s Third Law of Motion – Definition

Newton’s Third Law of Motion states that for every action, there is an equal and opposite reaction. This means that in every interaction, there is a pair of forces acting on the two interacting objects. The size of the forces on the first object equals the size of the force on the second object. Understanding this law is crucial in physics as it explains how forces come in pairs and how they affect objects.

What is the Best Example of Newton’s Third Law of Motion?

A classic example of Newton’s Third Law is the action of a rocket launching. As the rocket burns fuel, it expels exhaust gases downward (action), and in response, the rocket is propelled upwards (reaction). This demonstrates the principle of action and reaction forces working in tandem, a vivid illustration of the law in a real-world context.

Newton’s Third Law of Motion Formula

Newton’s Third Law of Motion is more of a principle rather than a formula, and it is typically stated as: “For every action, there is an equal and opposite reaction.” This law describes the nature of forces and how they interact but doesn’t provide a specific mathematical formula like some other laws of motion.

However, the concept can be expressed in a formula-like notation to illustrate the principle:

F_action = -F_reaction

In this expression:

• F_actionrepresents the force exerted by the first object on the second object.
• F_reaction represents the force exerted by the second object on the first object.
• The negative sign indicates that these two forces are equal in magnitude but opposite in direction.

22 Newton’s Third Law of Motion Examples

Newton’s Third Law of Motion, stating that every action has an equal and opposite reaction, is a key concept in understanding the dynamics of force interactions. This collection of 22 examples provides a broad spectrum of how this law operates in various scenarios, from simple daily activities to complex scientific phenomena. These examples are valuable for teachers, offering clear and relatable instances that demonstrate the reciprocal nature of forces, enhancing students’ comprehension of fundamental physical principles.

1. Rocket Launch: As the rocket expels exhaust gases downward, it propels upward.
2. Jumping off a Boat: Jumping forward pushes the boat backward.
3. Rowing a Boat: Oars push water backward, moving the boat forward.
4. Bouncing a Ball: The ball exerts force on the ground and is pushed up.
5. Swimming: Pushing water backward propels the swimmer forward.
6. Recoil of a Gun: Firing a bullet forward pushes the gun backward.
7. Walking: Feet push the ground backward, moving the body forward.
8. Pushing a Wall: Exerting force on a wall results in an equal force back.
9. Hitting a Baseball: The bat exerts force on the ball, and the ball exerts an equal force back on the bat.
10. Trampoline Jumping: Pushing down on the trampoline springs propels you upward.
11. Paddling a Kayak: The paddle pushes water back, moving the kayak forward.
12. Car Braking: Brakes apply force to wheels, wheels exert equal force back on brakes.
13. Sitting on a Chair: Your body exerts a downward force, and the chair pushes back up.
14. Skateboarding: Pushing the ground backward propels the skateboard forward.
15. Bird Flying: Wings push air down and backward, lifting the bird up.
16. Airplane Takeoff: Engines thrust air backward, moving the plane forward.
17. Playing Tug of War: Forces exerted by each team are equal and opposite.
18. A Book Resting on a Table: The book exerts a downward force; the table exerts an equal upward force.
19. Climbing Ladders: Pushing down on a rung raises the body up.
20. Kicking a Soccer Ball: The foot applies force to the ball, and the ball applies an equal force to the foot.
21. Leaf Blower: Blows air forward, pushing the blower backward.
22. Dropping an Anchor: The anchor exerts force on the seabed, stabilizing the boat.

Newton’s Third Law of Motion Examples In Everyday Life

Newton’s Third Law of Motion, highlighting action and reaction forces, is evident in numerous aspects of everyday life. This principle explains how interactions between objects involve reciprocal forces. These examples from daily life provide a clear understanding of the law’s practical implications, demonstrating its relevance in common activities. By observing these instances, students can appreciate how this fundamental law of physics plays a role in their everyday experiences.

Examples:

1. Closing a Drawer: Pushing the drawer in causes an equal force pushing back on your hand.
2. Sitting on a Swing: Pushing against the ground propels the swing in the opposite direction.
3. Using a Broom: When you push the broom forward, it exerts an equal force backward.
4. Stepping off a Curb: Your foot pushes down on the curb, which pushes back, aiding in stepping down.
5. Spraying with a Hose: The water jets out one way, pushing the hose back in the opposite direction.

Newton’s Third Law of Motion Examples In Real Life

In real life, Newton’s Third Law of Motion is constantly at play, governing the interaction of forces. These examples showcase the law in various real-life scenarios, emphasizing how actions and reactions are an integral part of our physical world. They serve as excellent demonstrations for educators to illustrate the concept’s ubiquitous presence.

Examples:

1. Using a Stapler: Pressing down on the stapler causes it to push the staples out.
2. Trimming with Scissors: As you close the scissors, the blades apply forces against each other to cut.
3. Driving a Nail with a Hammer: The hammer exerts force on the nail, which exerts an equal force back onto the hammer.
4. Lifting a Grocery Bag: You pull up on the bag, and the bag pulls down on your hand.
5. Playing on a Seesaw: When one person pushes down, the opposite end goes up.

Newton’s Third Law of Motion Examples In Daily Life

Newton’s Third Law of Motion is not just a theoretical concept; it’s a practical aspect of daily life. Understanding how this law operates in everyday situations helps demystify physics and highlights its real-world applications. These examples are relatable and easy to observe, making them great teaching tools.

Examples:

1. Opening a Door: Pushing the door forward causes an equal force pushing back on your hand.
2. Vacuuming: The vacuum cleaner pulls dirt in one direction, while the motor exerts force in the opposite direction.
3. Mopping the Floor: Pushing the mop forward results in an equal force in the opposite direction.
4. Getting Out of a Chair: Pushing down on the armrests helps to lift your body up.
5. Dragging a Suitcase: Pulling the suitcase initiates an equal force in the opposite direction.

Newton’s Third Law of Motion Examples In Sports

Sports offer a myriad of examples of Newton’s Third Law of Motion. These instances highlight how athletes and sports equipment interact through action-reaction forces. Understanding these examples can enhance both the comprehension of the law and its application in sports strategies and techniques.

Examples:

1. Boxing Punch: A boxer’s punch exerts force on the opponent, and an equal force is exerted back onto the boxer’s hand.
2. Jumping in Basketball: The player pushes down on the ground, and in return, the ground pushes them up.
3. Soccer Player Kicking the Ball: The player’s foot exerts force on the ball, and the ball exerts an equal and opposite force back on the foot.
4. Swimming Strokes: Swimmers push water backward to propel themselves forward.
5. Tennis Serve: The racket exerts a force on the ball, and the ball exerts an equal force back on the racket.

Importance of Newton’s Third Law of Motion

Newton’s Third Law of Motion is a fundamental principle in physics, pivotal in understanding how forces interact in our universe. This law states, “For every action, there is an equal and opposite reaction.” Its significance lies in its universal applicability, from explaining everyday phenomena to advanced scientific concepts. Understanding this law is crucial for students as it lays the foundation for comprehending dynamics in various fields.

1. Foundational Principle: Serves as a basic understanding of physical interactions.
2. Universal Application: Applies to all force interactions, regardless of the environment.
3. Scientific Inquiry: Encourages analytical thinking in observing everyday actions.
4. Technological Advancements: Underpins engineering and technological innovations.
5. Space Exploration: Essential for understanding rocket propulsion and spacecraft movements.
6. Sports Dynamics: Explains the forces involved in sports and physical activities.
7. Physics Education: Integral part of curriculum in physics and general science.
8. Environmental Understanding: Helps explain natural phenomena like tidal movements.
9. Safety Mechanics: Crucial in designing vehicles and safety mechanisms.
10. Biomechanics: Aids in the study of human and animal movements.

Application of Newton’s Third Law of Motion

The applications of Newton’s Third Law of Motion are vast and varied, impacting numerous aspects of our daily lives and scientific endeavors. This law’s simplicity masks its profound impact on how we understand and interact with the world around us.

1. Rocket Launches: Explains the thrust in rockets as they push against the Earth.
2. Walking and Running: Fundamental in how we move, with the ground pushing against our feet.
3. Vehicle Dynamics: Essential in understanding how cars accelerate and brake.
4. Water Sports: Explains the forces involved in activities like swimming and boating.
5. Aeronautics: Crucial for airplane lift and propulsion.
6. Building Structures: Helps in understanding stress and strain on structures.
7. Medical Devices: Applied in designing prosthetics and orthopedic supports.
8. Energy Conservation: Illustrates action-reaction pairs in momentum and energy exchanges.
9. Athletics Training: Used in analyzing and improving athletic performance.
10. Ecological Systems: Helps explain interactions in biological and ecological systems.

Teachers, these insights into Newton’s Third Law of Motion are designed to help you guide your students in understanding and applying this fundamental principle in both their academic studies and everyday observations. By relating this law to real-world examples, students can better appreciate its significance and develop a deeper interest in the wonders of physics.

Newton’s Third Law Worksheet

How to Calculate Newton’s Third Law

You can properly use Newton’s third law to help predict the displacement of the object or if the object has enough tension to maintain a hanging position. If you want to learn more about the 3 laws of Newton and Newton’s 3rd law, you may use any of Newton’s 3rd law examples and samples on the links above.

Step 1: Determine Which Formula You Will Need To Use

There are two formulas people can use to calculate Newton’s third law. T = W = mg for a free hanging mass and Fnet = T – W for movement. Determine which type of formula you will use for the specific problem.

Step 2: Write Down and Identify All the Variables

After you have determined the formula you will use, you must write down all the variables the problem has laid out for you. Be sure that each variable in the problem has the correct measurements, if they do not have the appropriate measurements be sure to convert them as necessary.

Step 3: Substitute the Variables for the Appropriate Things in the Formula

Substitute the given variables to the formula of net force or tension. This will give you the missing value you will need to find in the formula. Be sure to move the unidentified value to the left side of the equation by doing the appropriate steps.

Step 4: Solve the Solution

Solve for the missing value and be sure it will have the correct measurement associated with the missing value. If it doesn’t have the correct measurement, convert it accordingly.

FAQs

What are the uses of Newton’s third law?

Newton’s third law of motion allows people to know how much external force is required to disturb the equilibrium or balance of an object to move it in a specific direction. This is important as many of our basic actions and tools require movement. Newton’s third law will try to explain how much kinetic energy, mechanical energy, potential energy, or electrical energy is needed to disturb an object and move it a specific distance and direction.

What are real-life examples of Newton’s third law of motion?

We do many everyday actions that utilize Newton’s third law of motion. One real-life example of Newton’s third law of motion you can observe is when a person cuts wood products into small chunks using an ax. The person can unconsciously predict how much force they need to exert to change the raw wood commodity into a small wooden product. Another example we can observe is when a service tow truck tows a broken car to the nearest mechanic. The truck will need a specific amount of force to both tow the car and drive in a specific direction.

Newton’s third law of motion outlines how an object can displace another object with the appropriate amount of force. When planning to move something heavy or require a lot of energy, it is important to know how to be efficient when doing those said actions.