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Where does heat come from?

  1. Apr 10, 2010 #1
    For example

    If I extend and compress a spring numerous times the spring will increase in temperature.

    Where does the rise in temperature come from?

    The atoms that "make up" the spring from an atomistic point where does this rise in temperature come from?
     
  2. jcsd
  3. Apr 10, 2010 #2
    First off, temperature and heat are not the same thing.

    Heat is the energy transferred from one object to another due to a difference in temperature.

    Temperature is just the average kinetic energy of the molecules in a substance.
     
  4. Apr 10, 2010 #3
    Correct, it was a mistake however can be rationalized, with the fact that there is heat "caused by" the compression and extension of the spring.

    But the point is was, where does the temperature rise come from?

    Is your ans that the average KE is increased of the spring particles?
     
  5. Apr 10, 2010 #4
    From a rise in the kinetic energy of the substance. You put energy into the spring and the molecules reacted accordingly.
     
  6. Apr 10, 2010 #5
    But how does the KE rise if it is assumed that atoms are spheres which interact elastically?
     
  7. Apr 10, 2010 #6

    russ_watters

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    Staff: Mentor

    You just answered your own question: they don't quite act elastically.
     
  8. Apr 10, 2010 #7
    How do they interact then in this case?
     
  9. Apr 10, 2010 #8

    jack action

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    Science Advisor
    Gold Member

    In theory, a spring does not produce heat, because all energy used to compress it, is "stored" until it is released.

    In practice, metal spring can be deformed (sagging). If too much force is employed it can leads to rupture. This, obviously, means breaking molecular links (even deformation). When links are broken, energy is released in the form of heat.
     
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