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Equation Of State

  1. Mar 31, 2013 #1
    It is known that the combination of (p, v, t) gives Equation if State. Okay, what if we have the intervention of the internal as well, i.e, U=cte*PV for example. Can this be also considered as an equation of state?
  2. jcsd
  3. Mar 31, 2013 #2
    How do we know what U or cte are?
  4. Mar 31, 2013 #3
    Excuse me, U: internal energy. Cte any constant relating those variables. My case was cte=3/2
  5. Mar 31, 2013 #4


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    Staff: Mentor

    An equations of state is an equation that relates state variables, so yes, that would be an equation of state. Note that your example is just a trivial modification of the usual equation of state, due to the fact that there is a direct linear relation between U and T.
  6. Mar 31, 2013 #5


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    Gold Member

    If you give such a U (notice that it depends explicitly on some intensive parameters), it would be an equation of state. If you however give U in function of S, V and n (extensive parameters), you have all the information of the system and in such a case you'd have a fundamental equation from which you could derive up 3 equations of state.
  7. Apr 1, 2013 #6
    Thank you both for clearing things up!
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