In classical physics, the total energy of an object is the sum of its potential energy and its kinetic energy. Note that since all other forms of energy can be derived from these two types, the total energy is effectively the theoretical maximum amount of energy that could be taken from the object. Classical physics is physics based on principles developed before the rise of quantum theory, usually including the special theory of relativity and general theory of relativity. ... A physical body is an object which can be described by the theories of classical mechanics, or quantum mechanics, and experimented upon by physical instruments. ... Potential energy is stored energy. ... Kinetic energy (SI unit: the Joule) is energy that a body possesses as a result of its motion. ...

In modern physics, the total energy of an object is the sum of its rest energy its total kinetic energy, and its potential energy. The phrase modern physics may refer to: physics based on quantum mechanics (quantum physics) physics based on relativity physics based on both quantum mechanics and relativity 20th-century physics in general This is a disambiguation page: a list of articles associated with the same title. ... The rest energy of a particle is its energy when it is not moving relative to a given inertial reference frame. ... Potential energy is stored energy. ...