# Classical Mechanics

(redirected from*Classical system*)

Also found in: Dictionary, Thesaurus.

## Classical mechanics

The science dealing with the description of the positions of objects in space under the action of forces as a function of time. Some of the laws of mechanics were recognized at least as early as the time of Archimedes (287–212 b.c. ). In 1638, Galileo stated some of the fundamental concepts of mechanics, and in 1687, Isaac Newton published his *Principia*, which presents the basic laws of motion, the law of gravitation, the theory of tides, and the theory of the solar system. This monumental work and the writings of J. D'Alembert, J. L. Lagrange, P. S. Laplace, and others in the eighteenth century are recognized as classic works in the field of mechanics. Jointly they serve as the base of the broad field of study known as classical mechanics, or Newtonian mechanics. This field does not encompass the more recent developments in mechanics, such as statistical, relativistic, or quantum mechanics.

In the broad sense, classical mechanics includes the study of motions of gases, liquids, and solids, but more commonly it is taken to refer only to solids. In the restricted reference to solids, classical mechanics is subdivided into statics, kinematics, and dynamics. Statics considers the action of forces that produce equilibrium or rest; kinematics deals with the description of motion without concern for the causes of motion; and dynamics involves the study of the motions of bodies under the actions of forces upon them. For some of the more important areas of classical mechanics *See* Ballistics, Collision (physics), Dynamics, Energy, Force, Gravitation, Kinematics, Lagrange's equations, Mass, Motion, Rigid-body dynamics, Statics, Work

## Classical Mechanics

mechanics based on Newton’s laws of mechanics, dealing with the motion of macroscopic material bodies at speeds that are low in comparison with the velocity of light. The motion of particles at speeds of the order of the velocity of light is studied in the theory of relativity, and motion of microscopic particles is studied in quantum mechanics.