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{{About|closed [[physical system]]s as the term is used in the physical sciences|software (in computing) whose source code is kept secret|Closed source software}} | |||
The term '''closed system''' refers to a [[physical system]] that is closed to certain types of transfers in or out of the system. The specification of what types of transfers are excluded, is different in different contexts. | |||
== In physics == | |||
=== In classical mechanics === | |||
In [[Theory of relativity|nonrelativistic]] [[classical mechanics]], a closed system is a [[physical system]] which doesn't exchange any matter with its surroundings, and isn't subject to any [[force]] whose source is external to the system.<ref>{{cite book|last=Rana|first=N.C.|coauthors=P.S. Joag|title=Classical Mechanics|date=1991|page=78|isbn=978-0-07-460315-4}}</ref><ref>{{cite book|last=Landau|first=L.D.|authorlink=Lev Landau|coauthors=E.M. Lifshitz|title=Mechanics|edition=third|date=1976|page=8|isbn=978-0-7506-2896-9}}</ref> A closed system in classical mechanics would be considered an [[isolated system]] in thermodynamics. | |||
=== In thermodynamics === | |||
{{main|Thermodynamic system}} | |||
In [[thermodynamics]], a closed system can exchange energy (as [[heat]] or [[mechanical work|work]]) but not [[matter]], with its surroundings. | |||
An [[isolated system]] cannot exchange any heat, work, or matter with the surroundings, while an [[Thermodynamic system#Open system|open system]] can exchange all heat, work and matter. | |||
For a simple system, with only one type of particle (atom or molecule), a closed system amounts to a constant number of particles. However, for systems which are undergoing a [[chemical equilibrium|chemical reaction]], there may be all sorts of molecules being generated and destroyed by the reaction process. In this case, the fact that the system is closed is expressed by stating that the total number of each elemental atom is conserved, no matter what kind of molecule it may be a part of. Mathematically: | |||
<math>\sum_{j=1}^m a_{ij}N_j=b_i</math> | |||
where <math>N_j</math> is the number of j-type molecules, <math>a_{ij}</math> is the number of atoms of element ''i'' in molecule ''j'' and ''b''<sub>i</sub> is the total number of atoms of element ''i'' in the system, which remains constant, since the system is closed. There will be one such equation for each different element in the system. | |||
=== In relativistic physics === | |||
{{expand section|date=March 2013}} | |||
=== In quantum physics === | |||
{{see|Quantum field theory}} | |||
{{expand section|date=March 2013}} | |||
==In chemistry== | |||
In chemistry, a closed system is where no reactants or products can escape. | |||
==In engineering== | |||
In an [[engineering]] context, a closed system is a bound system, i.e. defined, in which every input is known and every resultant is known (or can be known) within a specific time. | |||
==See also== | |||
* [[Glossary of systems theory]] | |||
* [[Closed-circuit television]] (CCTV) | |||
* [[Dynamical system]] | |||
* [[Isolated system]] | |||
* [[Open system (system theory)]] | |||
* [[Thermodynamic system]] | |||
* [[Staged combustion cycle (rocket)|Closed cycle rocket engine]] | |||
==References== | |||
{{Reflist}} | |||
[[Category:Cybernetics]] | |||
[[Category:Concepts in physics]] | |||
[[Category:Physical systems]] | |||
[[Category:Systems theory]] | |||
[[Category:Thermodynamics]] | |||
[[de:Geschlossenes System]] |
Revision as of 23:47, 22 December 2013
29 yr old Orthopaedic Surgeon Grippo from Saint-Paul, spends time with interests including model railways, top property developers in singapore developers in singapore and dolls. Finished a cruise ship experience that included passing by Runic Stones and Church.
The term closed system refers to a physical system that is closed to certain types of transfers in or out of the system. The specification of what types of transfers are excluded, is different in different contexts.
In physics
In classical mechanics
In nonrelativistic classical mechanics, a closed system is a physical system which doesn't exchange any matter with its surroundings, and isn't subject to any force whose source is external to the system.[1][2] A closed system in classical mechanics would be considered an isolated system in thermodynamics.
In thermodynamics
Mining Engineer (Excluding Oil ) Truman from Alma, loves to spend time knotting, largest property developers in singapore developers in singapore and stamp collecting. Recently had a family visit to Urnes Stave Church. In thermodynamics, a closed system can exchange energy (as heat or work) but not matter, with its surroundings. An isolated system cannot exchange any heat, work, or matter with the surroundings, while an open system can exchange all heat, work and matter. For a simple system, with only one type of particle (atom or molecule), a closed system amounts to a constant number of particles. However, for systems which are undergoing a chemical reaction, there may be all sorts of molecules being generated and destroyed by the reaction process. In this case, the fact that the system is closed is expressed by stating that the total number of each elemental atom is conserved, no matter what kind of molecule it may be a part of. Mathematically:
where is the number of j-type molecules, is the number of atoms of element i in molecule j and bi is the total number of atoms of element i in the system, which remains constant, since the system is closed. There will be one such equation for each different element in the system.
In relativistic physics
In quantum physics
Template:See Template:Expand section
In chemistry
In chemistry, a closed system is where no reactants or products can escape.
In engineering
In an engineering context, a closed system is a bound system, i.e. defined, in which every input is known and every resultant is known (or can be known) within a specific time.
See also
- Glossary of systems theory
- Closed-circuit television (CCTV)
- Dynamical system
- Isolated system
- Open system (system theory)
- Thermodynamic system
- Closed cycle rocket engine
References
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My blog: http://www.primaboinca.com/view_profile.php?userid=5889534 - ↑ 20 year-old Real Estate Agent Rusty from Saint-Paul, has hobbies and interests which includes monopoly, property developers in singapore and poker. Will soon undertake a contiki trip that may include going to the Lower Valley of the Omo.
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