In physics, Coulomb's law is used to calculate the force between two charges that are at rest. It is a fundamental law in the field of electricity and magnetism. At the same time, it is totally connected with another, the law of gravity enunciated by Newton.
The statement of the law and its implications
Its postulate is as follows: the force exerted between two different electric charges is flatly proportional to the multiplication of both charges and, at the same time, it is inversely proportional to the square of the distance that separates them.
The formulation of Coulomb's law implies that if there are two charges with the same sign, they repel each other, that is, they move away. On the contrary, if we have two charges of different sign, they both attract. In this way, the electric force of attraction or repulsion depends on two factors: the intensity of the electric charge and the distance between the two.
It should be noted that Coulomb's law is only applicable to charges at rest in a given reference frame that is homogeneous and isotropic (for the medium to be homogeneous it has to present the same properties in any of its parts and for it to be isotropic it is It is necessary that the properties do not depend on the direction of measurement).
The 18th century and electricity
Electricity is a physical phenomenon that is related to the interaction between two particles, protons and electrons. The attraction that exists between the two makes it possible to explain all kinds of phenomena. In this sense, towards the middle of the eighteenth century the scientist Benjamin Franklin demonstrated that lightning from storms was actually a form of electricity in nature.
The French physicist Charles Coulomb (1736-1806) was the first scientist to quantify electrical forces and the results obtained were reflected in the law that bears his name. This law is considered a fundamental principle of electromagnetism and electrostatics.
Throughout the eighteenth century there were all kinds of theoretical and practical advances related to electricity: the first electric capacitors, the invention of the lightning rod, or an invention by Coulomb himself to accurately measure the force between electric charges. These and many other advances served as the foundation for the development of the Industrial Revolution.
Coulomb's invention for accurately determining the intensity of electric charges is known as the torsion balance and his unit of electric charge is called the coulomb (a coulomb is the amount of charge carried by a current of one ampere during one second).
Photo: Fotolia - Kuno