Coulomb's Law

Definition

Coulomb's law is a fundamental principle in electromagnetism that describes the force of interaction between two stationary electric charges. It states that the force between two point charges is directly proportional to the product of their magnitudes and inversely proportional to the square of the distance between them.

5 Must Know Facts For Your Next Test

1. Coulomb's law is a scalar equation, meaning the force between two charges has a magnitude but no direction.
2. The force between two charges can be either attractive or repulsive, depending on the signs of the charges.
3. The force between two charges is inversely proportional to the square of the distance between them, meaning as the distance increases, the force decreases rapidly.
4. Coulomb's law is applicable only for stationary, point-like charges, and does not account for the effects of moving charges or the shape of the charges.
5. Coulomb's law is a conservative force, meaning the work done in moving a charge between two points is independent of the path taken.

Review Questions

• Explain how Coulomb's law relates to the concept of conservative and non-conservative forces.
  • Coulomb's law describes the conservative force between two stationary electric charges. Since the work done in moving a charge between two points is independent of the path taken, the force is considered conservative. This means that the total work done on a charge moving through an electric field is determined solely by the initial and final positions of the charge, not the specific path it takes. In contrast, non-conservative forces, such as friction, depend on the path taken and cannot be described by a potential energy function.
• Describe how the electric force between two charges changes as the distance between them is increased.
  • According to Coulomb's law, the electric force between two charges is inversely proportional to the square of the distance between them. This means that as the distance between the charges increases, the electric force decreases rapidly. For example, if the distance between two charges is doubled, the electric force between them will decrease by a factor of four (1/2^2 = 1/4). This inverse square relationship is a fundamental characteristic of Coulomb's law and highlights the importance of the distance between charges in determining the strength of the electric force.
• Analyze the role of Coulomb's law in the context of conservative and non-conservative forces, and explain how it can be used to predict the behavior of charged particles in electric fields.
  • Coulomb's law is a fundamental principle that describes the conservative force between stationary electric charges. Since the work done in moving a charge through an electric field is path-independent, the electric force can be derived from a potential energy function, making it a conservative force. This allows for the prediction of the behavior of charged particles in electric fields using the principles of potential energy and conservative forces. For example, the motion of a charged particle in a uniform electric field can be determined by applying Coulomb's law and the associated conservative force, which will cause the particle to accelerate in the direction of the electric field. In contrast, non-conservative forces, such as friction, cannot be described by a potential energy function and do not follow the same predictable patterns as conservative forces like Coulomb's law.

Related terms

Electric Charge: The fundamental property of some subatomic particles that causes them to experience and generate electromagnetic forces.

Electric Force: The force of attraction or repulsion between electrically charged particles, as described by Coulomb's law.

Electric Field: The region surrounding a charged particle or object where a force would be exerted on another charged particle.