Coulomb's Law: Definition, statement, mathematical expression, and its units. The principle of Superposition of Forces.
Coulomb's Law
Coulomb's law is a fundamental law of electrostatics that describes the interaction between two charged particles. The law was discovered by French physicist Charles-Augustin de Coulomb in 1785.
Statement:
Coulomb's law states that the force of attraction or repulsion between two charged particles is directly proportional to the product of their charges and inversely proportional to the square of the distance between them. The force is along the line joining the two charges and is given by the following equation:
F = k * (q1 * q2) / r^2
where F is the force between the two charges, q1 and q2 are the charges of the two particles, r is the distance between the two charges, and k is the proportionality constant known as Coulomb's constant. The value of k is 9 x 10^9 N m^2 C^-2.
Units:
The SI unit of charge is Coulomb (C), the SI unit of distance is meter (m), and the SI unit of force is Newton (N). Therefore, the SI unit of Coulomb's constant is N m^2 C^-2.
Principle of Superposition of Forces:
The principle of superposition of forces states that the total force on a charge due to multiple charges is the vector sum of the forces due to each individual charge acting alone. In other words, the net force on a charge in the presence of other charges is the vector sum of the forces acting on that charge due to each of the other charges individually. This principle is based on the fact that the force between two charges is a conservative force, which means that it depends only on the positions and charges of the particles and not on the path taken by the charges.
