Newton’s Laws Of Motion: Definition, Formula, Applications And Examples

What Are Newton’s Laws Of Motion? 

Definition: The laws of motion are fundamental principles in physics that describe the relationship between the motion of an object and the forces acting on it. 

These laws were formulated by Isaac Newton. This article explores Newton’s three laws and provides a deep understanding on their implications. 

• Starting with Newton’s first law of motion, we delve into how objects behave when they are at rest or in uniform motion. 
• The second law unravels the relationship between mass, acceleration and external forces. 
• The third law of motion delves into the concept of action and reaction which is the opposing forces. 

Newton's Three Laws Of Motion

1. Newton’s First Law Of Motion: Law Of Inertia

The law describes an object’s tendency to resist changes in a state of motion. See the breakdown of the law here. 

Objects at rest stay at rest: If an object isn’t moving, it will remain the same unless a force pushes or pulls it. 

Objects in motion stay in motion: If an object is already moving, it will continue moving at the same speed and in a straight line unless a force acts on it. 

Some everyday examples and applications of this first law of motion are: 

• Passengers lurch forward when a bus suddenly breaks because their bodies tend to stay in motion while the bus slows down.
• Wearing a seat belt in the car while driving is an example of Newton’s first law of motion. 

2. Newton’s Second Law Of Motion: The Law Of Acceleration

The law is all about how the forces affect the objects' motion. It talks about the acceleration of motion that depends on the net force acting and the object's mass.

Well, if we talk about this law in an equation form then it is F=ma. Here, F is the force, m is the mass and a is the acceleration. 

Some everyday examples and applications  of the second law of motion are: 

• Kicking a ball- When you kick a ball, the force exerted is on the foot that causes the ball to accelerate in that direction. 
• Sports: Kicking a soccer ball - The harder you kick the ball (apply more force), the faster and farther it travels (greater acceleration).

3. Newton’s Third Law Of Motion- Law Of Action-Reaction or The Law Of Opposing Forces

You must have heard of this line, for every action there is an equal and opposite reaction. This is what the third law of motion talks about. 

It can be explained in a way- If Object A exerts a force on Object B, then Object B will also exert an equal and opposite force on Object A and that too in the opposite direction. 

The equation form for the third law of motion is as follows: FA = -FB

Some everyday examples and applications are as follows: 

Swimming pool: While swimming, when you push back on the water with your arms and legs, the water pushes back on you with an equal force, that propels you forward. 

A book lying on the table: The weight of books is acting in the downward direction on the table. While the reaction acts in the upward direction on the books. 

Conclusion: To learn about Newton’s three laws of motion, students can take a look at this article which can help them to brush up the concepts in easy words. 

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