Physics Mechanics, the branch of physics that focuses on the behavior and motion of objects under the action of given forces, is a fundamental discipline in understanding the physical world around us. Classical mechanics, as it is often called, establishes rules that describe the motion of every object in the universe — from particles to galaxies, as well as everyday experiences and forces like gravity and friction. Elements within this field include kinetics, kinematics, dynamics, and statics; addressing concepts such as inertia, inertia, momentum, force, torque, rotational motion, and energy. Mechanics is built on Isaac Newton’s three laws of motion — the law of inertia, the law of acceleration, and the law of action-reaction — though it can also be formulated from the least action principle or Hamilton’s principle.
Combined with accurate measurements and mathematical skills, these can be used to predict a system’s future behavior given its current state. The rules and principles of mechanics are so reliable that they are used in all scientific and engineering disciplines, from designing bridges and buildings to understanding the orbits of planets. Despite its foundational role, Mechanics also seeds more modern theories such as general relativity and quantum physics.