Mechanics
Introduction
Mechanics is a branch of physics that deals with the motion of objects and the forces that cause this motion. It is a fundamental discipline within physics, providing the basis for all physical sciences and engineering. Mechanics can be divided into two main branches: classical mechanics and quantum mechanics.
Classical Mechanics
Classical mechanics describes the motion of macroscopic objects, from projectiles to parts of machinery, as well as astronomical objects, such as spacecraft, planets, stars, and galaxies. It produces very accurate results within these domains, and is one of the oldest branches of physics.
Newton's Laws of Motion
The foundation of classical mechanics is Newton's laws of motion, which were formulated by Sir Isaac Newton in the 17th century. These laws describe the relationship between a body and the forces acting upon it, and its motion in response to those forces.
Conservation Laws
Conservation laws play a crucial role in classical mechanics. These include the conservation of energy, conservation of momentum, and conservation of angular momentum. These laws state that the total amount of each quantity remains constant in a closed system.
Quantum Mechanics
Quantum mechanics is a branch of physics dealing with physical phenomena at microscopic scales, where the action is on the order of the Planck constant. It departs from classical mechanics primarily at the quantum realm of atomic and subatomic length scales.
Wave-Particle Duality
One of the key features of quantum mechanics is the wave-particle duality. This principle states that every particle or quantum entity may be described as both a particle and a wave.
Uncertainty Principle
The uncertainty principle, formulated by Werner Heisenberg, is another fundamental concept of quantum mechanics. It states that the more precisely the position of a particle is known, the less precisely its momentum can be known, and vice versa.
Applications of Mechanics
Mechanics has a wide range of applications, from designing bridges and buildings in civil engineering to understanding the motion of celestial bodies in astrophysics. In technology, applications of mechanics include the design of vehicles, machinery, and simple devices such as levers and pulleys.