Coulomb's Law
* States: The force between two point charges is directly proportional to the product of the charges and inversely proportional to the square of the distance between them.
* Formula:
* F = k * (q1 * q2) / r²
* F = Force (measured in Newtons, N)
* k = Coulomb's constant (approximately 8.98755 × 10⁹ N⋅m²/C²)
* q1 and q2 = magnitudes of the two charges (measured in Coulombs, C)
* r = distance between the charges (measured in meters, m)
Key Points:
* Attraction and Repulsion: Like charges (both positive or both negative) repel each other. Unlike charges (one positive and one negative) attract each other.
* Inverse Square Law: The force decreases rapidly as the distance between the charges increases. If you double the distance, the force becomes four times weaker.
* Magnitude and Direction: The force is a vector quantity, meaning it has both magnitude (strength) and direction.
* Superposition Principle: The force between multiple charges is the vector sum of the forces between each pair of charges.
Examples
* Static Electricity: When you rub a balloon on your hair, you transfer electrons, creating static charges. These charges create forces that can cause your hair to stand on end.
* Electromagnetism: The force between two magnets is due to the magnetic fields generated by moving charges within the magnets.
* Atoms: The attraction between the positively charged nucleus and the negatively charged electrons in an atom is governed by Coulomb's law.
In Summary
Charge is the fundamental property that creates electric force. The strength of the force depends on the magnitudes of the charges and the distance between them. Coulomb's Law is a fundamental law of physics that describes this relationship.
