The Great 3 Laws of Motion According to Newton

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Updated on: Educator Review By: Michelle Connolly

The laws of motion developed by Sir Isaac Newton explain the connection between a physical object and the forces that act upon it. By understanding this information, we can construct the foundation for modern physics.

Newton's laws of motion
laws of motion

 Newton’s laws of motion are three laws that explain how objects move in response to applied forces. They were first published in 1687 and have since become fundamental principles in physics.  And considered laws Isaac Newton, an English mathematician and physicist, is credited with being the first person to formulate. The relationship between the forces acting on the body and the motion of the body. 

These relations are the basis of classical mechanics and are described here.

Newton’s First Law States that :

If a body is resting or moving in a straight line at a constant speed, it will continue to do so unless a force acts upon it. 

If a force acts upon it, it will change its speed or stop moving in a straight line altogether. In fact, In classical Newtonian mechanics, there is no significant difference between rest and linear motion. Stationary and constant-velocity motion in a straight line can be considered the state of motion seen by another observer in which one observer is moving. 

One moves at the same speed as the particle, and the other moves at a constant velocity relative to the particle.  In other words, rest and uniform motion in a straight line are regarded as the same state of the Laws of Motion. 

The concept behind this postulate is referred to as the Law of inertia.

Galileo Galilei was the one who initially conceptualised the Law of Inertia of Horizontal Motion on Earth.

René Descartes was the one who went on to generalise the concept. To the untrained eye, the principle of inertia may not appear as intuitively obvious as the starting point and basic assumption of classical mechanics. An object that is not pushed tends to rest, according to Aristotelian mechanics and also according to everyday experience.

Galileo’s experiments with balls rolling down inclined planes provided the basis for his derivation of the Law of inertia.

For Galileo, the principle of inertia was essential to the completion of his primary scientific endeavour, which required him to explain how it was possible for us to be unaware of the motion of the Earth, despite the fact that it was rotating on its axis and moving around the Sun. 

You can use the concept of inertia to find the answer given that we are moving along with the Earth and that our inclination is to keep moving in the same direction; Earth appears to be still to us even though we are moving. Therefore, the principle of inertia, which is not a statement of the obvious, was at one time the primary focus of debate in the scientific community.

Newton was able to accurately calculate small deviations due to the non-uniform movement of the Earth’s surface in a straight line.  Newton’s discovery that the motion of the Earth’s surface is not a constant motion in a straight line made this outcome conceivable.

The widespread observation that unforced bodies have a tendency to return to their resting positions is attributed to the fact that, according to the Newtonian formulation, to the fact that these bodies have forces acting on them that are unbalanced, such as friction and air resistance. This is a common observation.

Example of Newton’s First Law of Motion in Everyday Life 

Newton's laws of motion
The first Law of motion

If you jump out of a moving car or bus,  the ground exerts an effect on your feet, and your feet become immobile. You are going to fall because the top half of your body did not stop moving, and you will fall in the same direction you were going in before. – If there is no external force acting on a stationary object, then the object will not move.

– A moving object will continue to move even in the absence of any external forces…

Newton’s second Law – laws of motion: F = ma

The second laws of motionNewton's second law
the force applied to a body produces a proportional acceleration – Newton’s second Law presented with sticky notes and white chalk handwriting on a blackboard

Newton’s Second Law:

 It is a quantitative description of the change in motion of a body due to a force. The rate of change with time of the direction and magnitude of an object’s momentum is equal to the force exerted on the object. The angular momentum of an object equals its mass multiplied by its velocity.

Momentum, like velocity, is a vector quantity that has both magnitudes. And direction. A force acting on the body can change the magnitude or direction of the impact or both. One of the most important laws is Newton’s Second Law, one of the Laws of Motion in all physics. An object of constant mass m can be written as F = ma. 

Where both force (F) and speed (a) are vector quantities.

An object with a net force will accelerate according to the Second Law. It is assumed that there is no net force acting on the body either because there is either no force or the opposite force balances all forces. The body will then be in equilibrium without acceleration. Instead, we can conclude that an object with inertia has no net force.

Example of Newton’s Second Law of Motion in Everyday Life 

As we know of the laws of motion, According to Newton’s Second Law of Motion, acceleration, or the process of picking up speed, takes place whenever a force is applied to a mass (object). Riding a bicycle is a great demonstration of how this law of Motion works in practice. The mass is represented by your bicycle. The force is provided by your leg muscles as they push down on the pedals of your bicycle.

Newton’s third law: F = G(m1m2)/R2

The Third law of motion
Gravity vector illustration. Explained natural force to objects with mass—basics of universe physics. Gravitation gives weight to physical spacetime: Newton’s law formula, universe and apple example.

The most famous laws of Newton are the laws of motion (Third Law, action and reaction)

Newton’s Third Law states that when two objects interact, equal and opposite forces act on each other. The third Law is also called the Law of action and reaction. 

This Law is important in the analysis of static equilibrium problems where all forces are in equilibrium, but it also applies to objects in uniform or accelerated motion. 

The power it describes is real, not just a calculating tool.

 For example, a book placed on a table exerts a downward force equal to the table’s weight. 

According to the third Law, the tables give the cards equal and opposite forces.

 This force causes the table to deform slightly under the weight of the book, pressing the book like a spring.

An object with a net force will accelerate according to the second Law of the laws of motion. An object can be in equilibrium without acceleration if there is no force acting on it, either because there is no force at all or because opposing forces exactly balance all forces. 

Conversely, we can conclude that an object found to have no acceleration has no net force.

Example of Newton’s Third Law of Motion in Everyday Life 

The third laws of motion
Newton’s 3rd Law. The mutual actions of two bodies upon each other are always equal and directed to contrary parts.

It asserts, “There is an equal and opposite reaction to every action.”

The force that the first object exerts on the second when two objects interact is referred to as action. The reaction force is the force that the second body exerts on the first. Therefore, the action and its equal and opposite reactions are of equal magnitude.

Examples based on Newton’s third Law, one of the laws of motion.

– When a bullet is fired from a gun, the gun imparts a force that propels the bullet forward. In reverse, the bullet exerts an equal amount of force on the rifle.

An open book on a table: On the table, the weight of the books is exerting a downward force (action). While the reaction affects the books in an upward direction,

-When you jump, the force of your legs striking the ground causes the ground to respond by applying a force equal and opposite to the first, which launches you into the air.

– During swimming, the swimmer advances. As the swimmer pushes against the water, the water pushes back on the swimmer.

Influence of Newton’s laws

Effect of Newton’s Law

  • Newton’s laws first appeared in his masterpiece Principia Mathematica (1687). 
  • And are also known as “Principles”. In 1543, Nicolaus Copernicus proposed that the Sun could be the centre of the universe instead of the Earth. Meanwhile, Galileo, Johann Kepler, and Descartes replaced the Aristotelian worldview inherited from ancient Greece and laid the foundation for a new science explaining the workings of the heliocentric universe. 
  • In the Principia, Newton created a new science. He was able to develop his three laws. Explain that a planet’s orbit is an ellipse, not a circle, but as a result, it explains much more. 
  • The sequence of events from Copernicus to Newton is called a scientific revolution.

 And R divided by the square of the distance: F = G(m1m2)/R2.

Isaac Newton proposed this Law in 1687 and used it to explain the observed movements of the planets and the moon. 

  • It was formulated mathematically by Johannes Kepler in the early 1600s.
  • All three of Newton’s laws apply to objects regardless of their size or whether or not they are made of different materials. 
  • This fact makes them useful when modelling objects of various sizes and compositions because they can be applied uniformly across all objects. 

There are some exceptions:

– Newton’s laws do not apply in some situations, such as when an object is moving close to the speed of light.

 – In addition, they do not apply when dampening forces oppose the motion, such as friction or air resistance. For this reason, these laws should be interpreted with care and applied carefully when modelling the motion of objects.

– Many people believe that Newton’s First Law does not apply in some cases for beginners. 

This is because many things that happen in daily life occur without being pushed, such as objects falling due to gravity.

 – In addition, many people believe that this Law does not apply because objects at rest can also be pushed by other forces, such as wind or water currents.

– In general, many people believe this Law does not apply because there are many forces at work other than gravity.

– Others believe that Newton’s Second Law does not apply in some cases to advanced students. This is because many students do not know their mass or how to measure their acceleration due to gravity.

– In addition, many students do not know how to calculate force, which makes it difficult to understand Newton’s Second Law. 

This makes it difficult for many students to apply Newton’s second Law in everyday life.

– Some believe that Newton’s Third Law does not apply in some cases to everyone.

 This is because many people believe that this Law does not apply when considering human interaction or moral responsibility.

 In addition, some people believe that it does not apply when considering projectiles and explosions because they occur in different directions.

Some people do not agree with Isaac Newton’s laws of motion and gravity because they are controversial and open to interpretation.

 For example, some disagree with his laws because they do not apply in all situations and can be difficult to interpret accurately. Others disagree with his laws because they do not agree with his interpretation of gravity and motion.

Ultimately, Isaac Newton’s laws of motion are universally accepted because they are useful for modelling the motion of objects under the influence of applied forces. 

However, there are some exceptions because these laws can be difficult to interpret accurately and difficult for beginners to understand. 

Therefore, it is important to understand what these laws mean before applying them since they can also be difficult for advanced students to understand.

If you check the last details we provided, you will find that you have the necessary basic information about Newton’s laws of motion. Keep on visiting Learning Mole to learn a lot more about everything out there.

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