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This energy is stored as a result of the elevated position of an object such as a rock on top of a hill or water behind a dam. It is written as
where is the mass of the object, the acceleration due to gravity and the height above a chosen reference level (typical units would be kilograms for , metres/second2 for , and metres for ).
In relation to spacecraft and astronomy g is not constant and the formula becomes an integral. In the case of a sphere of uniform mass (such as a planet), with h measured above the surface, the integral takes the form:
Where is the radius of the sphere, M is the mass of the sphere, and G is the gravitational constant.
If h is instead taken to be the distance from the center of the sphere, then outside the sphere the potential energy relative to that at the center has two terms:
which evaluates to:
[We may also want to link to an explanation of that second term (the gravitational forces created by hollow spherical shells)]
A frequently adopted convention is that an object infinitely far away from an attracting source has zero potential energy. Relative to this, an object at a finite distance r from a source of gravitation has negative potential energy. If the source is approximated as a point mass, the potential energy simplifies to:
See also Gravitational binding energy.
This energy is stored as the result of a deformed solid such as a stretched spring. As a result of Hooke's law, it is given by:
where is the spring constant, expressed in N/m, and is the displacement from the relaxed position, expressed in metres.
Chemical energy is a form of potential energy related to the breaking and forming of chemical bondIn chemistry, a chemical bond is the force which holds together atoms in molecules or crystals. In many simple compounds, valence bond theory and the concept of oxidation number can be used to predict molecular structure and composition. Similarly, theoris.
where E0 is the rest massMass is a property of physical objects that, roughly speaking, measures the amount of matter they contain. It is a central concept of classical mechanics and related subjects. Strictly speaking, there are two different quantities called mass Inertial mass energy, m is mass of the body, and c is the speed of lightCherenkov effect in a "swimming pool" nuclear reactor. The effect is due to electrons moving faster than the speed at which light moves in water. The speed of light (denoted as c reputedly from the Latin celeritas "speed", and also known as Einstein's con in a vacuumThe article on the vacuum cleaner is located elsewhere. In physics, a vacuum is the absence of matter in a volume of space. A partial vacuum is expressed in units of pressure. The SI unit of pressure is the pascal (abbreviated to Pa in usage). It can also. (The subscript zero is used here to distinguish this form of energy from the others that follow. In most other contexts, the equation is written with no subscript.)
The rest mass energy is the amount of energy inherent in the mass when it is at rest. This equation quantifies the equivalence of mass and energy: A small amount of mass is equivalent to a very large amount of energy. (i.e., 90 petaThis article describes the SI prefix peta . For other meanings, see Peta (disambiguation In physics and mathematics, peta (symbol: P is a prefix in the SI system of units denoting 1015, or 1,000,000,000,000,000. For example: 1 petametre 1015 metres 1 petajoule/kg ≈ 21 megatonA megaton (symbol MT or Mt is 1,000,000 tons, i. It is also used as a unit of energy, approximately equivalent to the energy released in the detonation of this amount of TNT. A kiloton is one-thousandth of a megaton approximately equivalent to 1,000 tonss/kg)
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