Applications of Newton’s Third Law

Newton’s Third Law states that for every action, there is an equal and opposite reaction. This principle has many applications in various fields, from everyday experiences like walking and swimming to complex systems like rocket propulsion and car collisions. In this article, we are going to learn about the various applications of Newton’s Third Law.

What is Newton’s Third Law?

Newton’s Third Law is about action and reaction. It says that for every action, there is an equal and opposite reaction. This law means that when one object pushes or pulls on another object, the second object pushes or pulls back with the same force but in the opposite direction.

For example, when you push against a wall, the wall pushes back on you with the same force. If you throw a ball against a wall, the ball exerts force on the wall, and the wall exerts force back on the ball, making it bounce back.

This law applies to all objects, whether big or small. It helps explain things like why rockets move forward when they expel gas backwards and why cars move forward when their tires push backwards against the road. Let’s learn in detail about real life applications of Newton’s Third Law of Motion

Real-Life Applications of Newton’s Third Law of Motion

Some real-life applications of newton’s third law of motions are:

Walking

When you walk, each step involves a series of actions and reactions. As your foot pushes backwards against the ground (action), the ground simultaneously exerts an equal and opposite force forward on your foot (reaction) due to friction. This reaction force propels you forward, allowing you to move.

• Action: When you push backward against the ground with your foot, the ground reacts by pushing forward on your foot with an equal force.
• Reaction: This reaction force from the ground propels you forward, allowing you to move.
• The force exerted by your foot backward is transferred to the ground, causing you to move forward due to the ground pushing back.
• Each step involves a series of actions and reactions between your feet and the ground, enabling you to walk efficiently.

Swimming

In swimming, as you push against the water with your arms and legs (action), the water pushes back with an equal force (reaction) according to Newton’s third law. This reaction force propels you forward, enabling you to swim through the water.

• Action: As you push against the water with your arms and legs, the water reacts by pushing back on your body with an equal force.
• Reaction: This reaction force from the water propels you forward, enabling you to swim.
• The force exerted by your arms and legs on the water is transferred back to your body, causing forward motion.
• Efficient swimming relies on generating strong enough action forces to overcome the resistance of the water.

Driving

When a car accelerates forward, the tires push backwards against the road (action) due to the friction between the tyres and the road surface.

• Action: When a car accelerates forward, the tires push backward against the road surface due to friction.
• Reaction: In response, the road exerts an equal and opposite force forward on the tires, propelling the car forward.
• The friction between the tires and the road allows the car to grip the road surface, translating the backward force from the tires into forward motion.
• This interaction between the tires and the road is essential for controlling the movement and speed of the vehicle.

Flying

In flight, an airplane’s engines expel exhaust gases backward with great force (action) according to Newton’s third law. As a result, the airplane experiences an equal and opposite force forward (reaction), allowing it to move through the air.

• Action: In flight, an airplane’s engines expel exhaust gases backward with great force.
• Reaction: As a result, the airplane experiences an equal and opposite force forward, allowing it to move through the air.
• The propulsion provided by the engines generates thrust, which propels the airplane forward.
• The interaction between the airplane and the air molecules allows for controlled flight and maneuverability.

Rowing

When rowing a boat, as you pull the oar backward through the water (action), the water exerts an equal and opposite force forward on the oar (reaction) due to drag. This reaction force propels the boat forward, allowing it to move across the water.

• Action: When you pull the oar backward through the water, the water reacts by exerting an equal and opposite force forward on the oar due to drag.
• Reaction: This reaction force from the water propels the boat forward, allowing it to move across the water.
• Efficient rowing involves applying force to the water in a way that minimizes resistance and maximizes forward propulsion.
• The action of rowing and the reaction from the water work together to propel the boat forward.

Jumping

When you jump, you push downward against the ground with your legs (action), and the ground exerts an equal and opposite force upward on your body (reaction) according to Newton’s third law. This reaction force propels you into the air, allowing you to jump.

• Action: When you push downward against the ground with your legs, the ground reacts by exerting an equal and opposite force upward on your body.
• Reaction: This reaction force from the ground propels you into the air, allowing you to jump.
• The force exerted by your legs on the ground is transferred back to your body, causing upward motion.
• The speed and height of your jump depend on the magnitude of the force applied and the reaction from the ground.

Rocket propulsion

In rocket propulsion, as the rocket’s engines expel exhaust gases backward with tremendous force (action), the rocket experiences an equal and opposite force forward (reaction) according to Newton’s third law. This reaction force propels the rocket forward through space.

• Action: In rocket propulsion, the rocket’s engines expel exhaust gases backward with tremendous force.
• Reaction: As a result, the rocket experiences an equal and opposite force forward, propelling it through space.
• The expulsion of exhaust gases creates thrust, which accelerates the rocket in the opposite direction.
• Rocket propulsion demonstrates Newton’s third law on a large scale, enabling spacecraft to travel vast distances in space.

Balloon-powered cars

In a balloon-powered car, as air is expelled backward from the balloon (action) due to the escaping air pressure, the car experiences an equal and opposite force forward (reaction) according to Newton’s third law. This reaction force propels the car forward along the ground.

• Action: As air is expelled backward from the balloon due to escaping air pressure, the car experiences an equal and opposite force forward.
• Reaction: This reaction force from the expelled air propels the car forward along the ground.
• The force exerted by the escaping air pushes the car forward, demonstrating Newton’s third law in action.
• Balloon-powered cars illustrate the principle of action and reaction, where the force of the expelled air moves the car in the opposite direction.

FAQs on Applications of Newton’s Third Law

What is an example of Newton’s Third Law?

An example is when you jump, your legs apply force to the ground, and the ground applies an equal and opposite force that propels you upward.

How does Newton’s Third Law apply to rockets?

Rockets launch into space by expelling gas downwards; the downward action forces the rocket upwards, demonstrating Newton’s Third Law.

What role does Newton’s Third Law play in walking?

When walking, your foot pushes against the ground, and in return, the ground pushes your foot back, helping you move forward.

Can Newton’s Third Law explain car motion?

Yes, when a car’s wheels push back on the road, the road pushes the wheels forward, moving the car.

How does Newton’s Third Law apply to swimming?

In swimming, when you push the water backwards with your arms, the water pushes you forward, enabling you to swim.

What is the significance of Newton’s Third Law in sports?

In sports like baseball, when the bat strikes the ball, the ball exerts an equal and opposite force back on the bat, affecting the ball’s motion.

How does Newton’s Third Law work in bird flight?

Birds fly by flapping their wings downward against the air, which in turn pushes them upwards and forwards due to the air’s reactive force.