Answer: In classical physics, there are several fundamental assumptions and principles that underlie the explanation of electrical forces. These assumptions help form the basis of electrostatics, the study of stationary electric charges. Here are the five basic assumptions and principles related to electrical forces:
Conservation of Charge: The fundamental assumption is that electric charge is conserved. This means that the total electric charge in a closed system remains constant over time. Charge cannot be created or destroyed; it can only be transferred from one object to another.
Existence of Positive and Negative Charges: Electric charges come in two types: positive and negative. Like charges (e.g., two positive charges or two negative charges) repel each other, while opposite charges (e.g., a positive charge and a negative charge) attract each other. This principle is known as the law of electrostatic attraction and repulsion.
Coulomb's Law: Coulomb's law describes the force between two point charges. It states that the force between two charges is directly proportional to the product of their magnitudes and inversely proportional to the square of the distance between them. The law is given by the equation:
Superposition Principle: The superposition principle states that the total electric force on a charged object is the vector sum of the forces exerted by all other charged objects in the system. In other words, the forces from individual charges add together according to vector addition principles.
Electrostatic Equilibrium: In the absence of external forces, charged objects will come to a state of electrostatic equilibrium. In this state, there is no net motion of charge, and the electric field is zero inside a conductor. This principle is fundamental to understanding the behavior of conductors and the distribution of charges on their surfaces.
These five assumptions and principles provide the foundation for explaining electrical forces and understanding the behavior of electric charges in a variety of situations. They are essential concepts in classical electrostatics and are used to describe and predict the behavior of electrically charged particles and objects.