Meaning of Classical Physics
What is Classical Physics:
Classical physics or Newtonian physics is a discipline that is based on the basic laws of motion on everyday objects.
Classical physics is known as such, with the publication in 1687 of Newton's Laws, a mathematical formulation of Isaac Newton (1643-1727) in his work Philosophiae naturalis principia mathematica. Newton's Laws are the basis of classical physics and mechanics.
Classical physics is divided into the following disciplines:
- Classical mechanics
- Hydrostatic and hydrodynamic
- Waves and optics
- Electricity and magnetism (later electromagnetism)
Difference between classical physics and modern physics
Modern physics was born in the 20th century with the birth, on the one hand, of Albert Einstein's General Theory of Relativity published in 1905 and, on the other hand, of quantum mechanics known as the science that studies the behavior of particles at the atomic and subatomic level.
See also Quantum Mechanics.
Quantum physics is based on Newton's three laws:
Newton's First Law or Law of Inertia
Newton's First Law states that an object will remain at rest or in Uniform Rectilinear Motion (M.R.U.) unless an external force acts on it.
This law only applies to standard problems of objects that have a net internal force of 0. Furthermore, objects are also characterized by the fiction of two forces: the force of circular motion and the force of gravity.
To exemplify Newton's first law, imagine a person turning on himself with his arms outstretched holding a rope with a ball at the end. The ball will have a circular orbit around the person. If the string breaks, the ball will follow the straight line where the string left the ball, drawing a uniform rectilinear motion.
See also Uniform rectilinear motion.
Newton's Second Law or Fundamental Principle of Dynamics
Newton's Second Law or Fundamental Principle of Dynamics was an advance in the study of movement, since it did not focus only on describing movement but on determining its causes by means of the following formula:
Where F represents the net force of the object, m is the mass of the object and a is the acceleration. This formula helps to study the results that the same force exerts on objects of different mass.
See also Newton's Second Law
Newton's Third Law or Action-Reaction Principle
Newton's Third Law stipulates that all the forces in the Universe occur in pairs, that is, they have a force of equal but opposite magnitude. This indicates the inexistence of isolated forces and constitutes one of the fundamental principles on the symmetry of the Universe.
The Third Law indicates that if there is an external force, that force will be counteracted by another equal but in the opposite direction. The Law also applies to the internal forces that keep it at rest in this way, since it will not be able to produce a net force on the entire system to put it in motion. Only interaction with another external object will be able to move it.