Glossary
Coulomb (C)
The SI unit of electric charge, defined as the amount of charge transported by a constant current of one ampere in one second.
Example:
A typical lightning bolt can transfer several Coulombs (C) of electric charge.
Coulomb's Constant (k)
A proportionality constant used in Coulomb's Law, representing the strength of the electric force in a vacuum. Its approximate value is 8.99 × 10^9 N·m²/C².
Example:
When calculating the force between two charges, you always multiply by Coulomb's Constant (k) to get the correct magnitude in Newtons.
Coulomb's Law
A fundamental law describing the magnitude of the electric force between two point charges. It states that the force is directly proportional to the product of the charges and inversely proportional to the square of the distance between them.
Example:
Using Coulomb's Law, we can calculate the exact attractive force between a positively charged ion and a negatively charged electron in a molecule.
Electric Charge
A fundamental property of matter that causes it to experience a force when placed in an electromagnetic field. It is measured in Coulombs (C).
Example:
An electron has a negative electric charge, while a proton has a positive electric charge.
Electric Field
A region of space around an electrically charged object where another charged object would experience an electric force. It is represented by field lines indicating the direction of force on a positive test charge.
Example:
If a positive charge is placed in an electric field pointing to the right, it will experience a force to the right.
Electric Force
A fundamental force that arises from the interaction between electrically charged objects, causing them to either attract or repel each other.
Example:
When you rub a balloon on your hair, the electric force causes your hair to stand on end as it's attracted to the charged balloon.
Gravitational Force
A fundamental attractive force between any two objects with mass. It is significantly weaker than the electric force at the atomic scale.
Example:
The gravitational force keeps planets in orbit around the sun, but it's negligible when considering the interaction between two electrons.
Inverse Square Law
A principle stating that the strength of a physical quantity (like electric force or gravitational force) is inversely proportional to the square of the distance from the source.
Example:
If you double the distance between two charged particles, the electric force between them decreases by a factor of four, illustrating the inverse square law.
Like Charges Repel, Opposite Charges Attract
A fundamental rule of electrostatics stating that objects with the same type of charge (both positive or both negative) push each other away, while objects with different types of charge (one positive, one negative) pull each other together.
Example:
Two positively charged protons will repel each other, while a positively charged proton and a negatively charged electron will attract each other.
Newton (N)
The SI unit of force, defined as the force required to accelerate a mass of one kilogram at a rate of one meter per second squared.
Example:
The electric force calculated between two charges is typically measured in Newtons (N).