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Energy transformation, also known as energy conversion, is the process of changing energy from one form to another. [1] In physics , energy is a quantity that provides the capacity to perform work or moving (e.g. lifting an object) or provides heat .
The energy that a physical body possesses due to its motion, defined as the work needed to accelerate a body of a given mass from rest to its stated velocity. The body continues to maintain this kinetic energy unless its velocity changes. Contrast potential energy. Kirchhoff's circuit laws. Also called Kirchhoff's rules or simply Kirchhoff's laws.
In physics and astronomy, a frame of reference (or reference frame) is an abstract coordinate system, whose origin, orientation, and scale have been specified in physical space. It is based on a set of reference points , defined as geometric points whose position is identified both mathematically (with numerical coordinate values) and ...
In physics, action is a scalar quantity that describes how the balance of kinetic versus potential energy of a physical system changes with trajectory. Action is significant because it is an input to the principle of stationary action, an approach to classical mechanics that is simpler for multiple objects. [1]
Since the object's velocity vector is constantly changing direction, the moving object is undergoing acceleration by a centripetal force in the direction of the center of rotation. Without this acceleration, the object would move in a straight line, according to Newton's laws of motion .
Specific rate of energy transfer (total normalized per unit area); [2] SI units: W⋅m −2 = J⋅m −2 ⋅s −1: This is a vector quantity, its components being determined in terms of the normal (perpendicular) direction to the surface of measurement. This is sometimes called energy flux density, to distinguish it from the first definition.
When something is exerting force on the ground, the ground will push back with equal force in the opposite direction. In certain fields of applied physics, such as biomechanics, this force by the ground is called 'ground reaction force'; the force by the object on the ground is viewed as the 'action'.
As the Universe grows, its temperature drops, which leaves less energy [per unit volume of space] available to perform work in the future than was available in the past. Additionally, perturbations in the energy density grow (eventually forming galaxies and stars). Thus the Universe itself has a well-defined thermodynamic arrow of time.