Amontonsféle

Amontons's Law, also known as Amontons's empirical law of friction or the first law of friction, is a fundamental principle in tribology, the science of friction, wear, and lubrication. It states that the frictional force between two surfaces is directly proportional to the normal force pressing them together and is independent of the apparent area of contact. This law was first described by the French physicist Guillaume Amontons in the early 18th century.

Mathematically, Amontons's Law can be expressed as F = μN, where F is the frictional force, μ is the coefficient of friction, and N is the normal force. The coefficient of friction (μ) is a dimensionless quantity that depends on the nature of the two surfaces in contact. For instance, the friction between rubber and asphalt will have a different coefficient than that between steel and ice.

While widely applicable and a useful approximation in many practical scenarios, Amontons's Law has limitations. It assumes that surfaces are perfectly smooth and that friction arises solely from intermolecular forces at points of contact. In reality, surfaces are rough, and friction is also influenced by interlocking asperities (microscopic irregularities) and adhesion. Despite these complexities, Amontons's Law remains a cornerstone for understanding and predicting frictional behavior in many engineering applications.