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Energy and matter equivalence

  1. Oct 11, 2014 #1
    The question was : describe the first law of thermodynamics. I said matter can't be created or destroyed. I got marked wrong, my argument will be that the laws of thermodynamics can be written in different ways. Einstein famous equation relates matter and energy. There is also the matter-energy equivalent theory. Is this a valid argument? If so what else can I say?
  2. jcsd
  3. Oct 11, 2014 #2
    Matter is not the same as mass. Matter is ill-defined in science and is a term that shouldn't really be used. Matter is not conserved.
  4. Oct 11, 2014 #3
    You can argue that as much as you like, but it's not a statement of the first law of thermodynamics. The first law is purely relates the change in internal energy to the heat flow into/out of the system and the work done/by the system.
  5. Oct 11, 2014 #4


    Staff: Mentor

    You were correctly marked wrong. You should not argue, you should learn from your mistake and do better next time. There are times when it is good to argue a grade, but this is not one of them.
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