Understanding Electrostatics: History, Matter, and Laws
Electrostatics: An Introduction
Electrostatics: It is the branch of physics that studies the phenomena of electricity produced by static charge distributions, i.e., the electrostatic field of a charged body.
Historical Development
Around 600 BC, the philosopher Thales of Miletus noted the ability of amber, after being rubbed, to exert attraction on small objects. Somewhat later, another Greek, Theophrastus (310 BC), undertook a study of the different materials that were capable of producing electrical phenomena, writing the first treatise on electricity.
In the beginnings and early seventeenth century, the first studies on electricity and magnetism began, designed to improve the accuracy of navigation with a magnetic compass.
Around 1672, the German physicist Otto von Guericke built the first electrostatic machine that could produce and store static electricity by friction.
In 1733, the Frenchman Francois de Cisternay du Fay suggested the existence of two types of electric charge: positive and negative.
In 1745, the first elements of accumulation of charges were developed: the capacitors developed at the University of Leiden by Jürgen Ewald von Kleist and Pieter Van Musschenbroeck.
In 1767, Joseph Priestley published his The History and Present State of Electricity on the history of electricity to date.
In 1785, the French physicist Charles Coulomb published a treatise describing the first quantitative electrical forces, formulating the laws of attraction and repulsion of static electric charges, using the torsion balance for their actions.
Throughout the century, subsequent advances occurred in the study of electricity, electrical phenomena produced by moving charges inside a conductor. Finally, in 1864, the Scottish physicist James Clerk Maxwell unified the laws of electricity and magnetism in a reduced set of mathematical laws.
Structure of Matter
Matter consists of extremely small particles clumped together to form the atom. There are 92 natural occurrences of clusters of particles called elements. These elements were grouped in the periodic table of elements in sequence according to their atomic numbers and atomic weight. There are also 14 man-made elements that do not occur in nature, so in the end, there are about 106 elements known to date. These elements cannot be changed by chemical processes. They can only be changed by nuclear reaction or nuclear processes, but can be combined to produce the countless numbers of compounds with which we encounter every day.
Key Concepts
- Simple Pendulum: A simple pendulum refers to an ideal entity consisting of a point mass suspended by a thread inextensible and weightless, able to swing freely in the frictionless vacuum.
- Electroscope: An instrument to determine the presence of electric charges and their signs.
- Electrical Conductor: A body that, when made contact with a body full of electricity, transmits it to all points of its surface. Generally elements, alloys, or compounds with free electrons that allow movement of loads.
- Insulator: A material which resists the flow of electrical current. It is an object intended to support or separate electrical conductors without passing current with itself.
- Semiconductor: A substance that behaves like a conductor or insulator, depending on the temperature of the environment in which it is.
Charging a Body
- Electrification by contact
- Electrification by rubbing
- Electrification by induction
Comparison Between Electric Charges and Gravitational Forces
The magnetic charges attract or repel with a formula similar to the gravitational force. They depend inversely with the square of the distance and directly with the product of the charges or the masses.
Coulomb’s Law
A common manifestation of electricity is the force of attraction or repulsion between two stationary bodies, in accordance with the principle of action and reaction, have the same electrical force on each other. The electrical charge of each body can be measured in Coulombs. The force between two particles with charges q1 and q2 can be calculated from Coulomb’s law.
According to which the force is proportional to the product of charges divided by the square of the distance that separates them. The proportionality constant K depends on the medium surrounding the charges.