What are Newton's laws?

Through this post you will have the opportunity to learn what are Newton's Laws, better known as Newton's laws of dynamics or motion, through them, the movement of the stars is known and the mechanical operation of the machines.

In order to know what Newton's laws are, one must know about the movement, responsible for the displacement of bodies, within a certain place with reference to another body, force is the action of one body on another, which that allows movement and mass is the magnitude that indicates the amount of matter that makes up the moving body.

For which Isaac Newton, assumes that the movement is a translation of a body that moves to another place, this movement and place can be relative, until reaching a stationary place, which opens the way to the reference system of the absolute movements.

Consequently, in Isaac Newton's approaches, force has an absolute and not a relative name, to which all movement is governed by three laws, which explain the movement of all macroscopic objects that are They move at speeds less than light, being the following:

Newton's First Law

It is known as the Law of Inertia, since there are no external forces acting on an object, it maintains rest or its movement will be a constant speed in a straight line, the movement ends when the external forces of friction they act on the surface of the body causing it to stop.

The motion of an object moving on an ice surface will last longer than on a concrete surface, because there is less friction on ice than on concrete; Galilei commented that in the absence of friction, the body would continue to move at a constant speed, since no force affects its movement.

When there is a change in the movement of a body, it will present a certain level of resistance known as INERTIA, the best example, when you travel in a car that had to brake in an emergency, you must stop with your own hands, there we experience what inertia is.

You can also appreciate the force in a bus, because when it stops unexpectedly, the people being transported will move forward, seeking to continue the rectilinear movement, but if it is at rest and moving quickly, people will have to move backwards , trying to find the idle state.

Newton's Second Law

It is the law of Force, says that if you apply force to a body, it will accelerate and this acceleration will occur in the same direction in which the force was applied, which is inversely proportional to the mass of the body that it moves.

It is essential that you remember that force and acceleration are vectorial magnitudes, so they have value, direction and sense; if the mass of the objects were continuous. This is the formula that expresses Newton's second Law is (F=m.a).

Now, when the mass of the body increases, the acceleration tends to decrease, which is why you need to establish the quantity of movement that is known as (p), which is equal to the product of the mass of a body by its speed . Expressed mathematically like this (p=m.v).

In the International System the amount of movement (p) is measured in kg.m/s, where the unit for mass is the kilogram and the unit for measuring acceleration is meters per second, so Force(N)=mass (kg) x acceleration (m/s2)

Newton's Third Law

It is called the Law of action and reaction, here it is postulated that the force that drives a body generates in turn an equal force that goes in the opposite direction, this means that if a body exerts force on another body, the second body will produce a force on the first with equal magnitude and in the opposite direction, this force is produced in equal and opposite parts

Newton's third law is expressed mathematically as F1 = F2'

A good example is when young A pushes young B in the pool, both will move in the opposite direction, although the latter does not attempt to push the first, this is a product of the reaction that young B does about young A.

It is essential to observe that this base of action and reaction relates two forces that are not applied to the same body, which produces different accelerations, according to their masses, each force separately obeys the second law, because although the pairs of action and reaction have an equal value and opposite directions, they do not cancel each other out, since they act on different bodies.

Who was Isaac Newton?

Isaac Newton (1643-1727), was a scientist of English origin, who together with Galileo transformed the foundations of classical mechanics. In the year 1867 he published his work entitled Philosophiae Naturalis Pincipia Mathematica, in the third volume of this compendium he presented his laws, which he combined with the Law of universal gravitation.

These laws are related to dynamics and revolutionized the basic concepts of physics and the movements of bodies in the cosmos, they have been valid for more than two centuries, the importance of these laws is that they transformed the basis of classical mechanics.

By combining these laws with the Law of Universal Gravitation, Kepler's Laws can be explained in terms of planetary movements, also allowing us to know the movement of rockets in space and the mechanical operation of machines.

Although Isaac Newton's dynamics, also known as classical dynamics, is only fulfilled in systems where the reference is inertial, so it can only be applied to objects that have nothing to do with the speed of the light, that does not approach the speed of 300,000 km/s.

This happens because at the moment an object reaches that speed, non-inertial reference systems occur, causing a series of factors known as relativistic effects or fictitious forces, which add terms that can explain the movement of a system enclosure of classical particles interacting with each other.

The study of these effects is observed mainly in the increase of mass and concentration of length and correspond to the theory of spatial relativity that Albert Einstein enunciated in 1905.


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