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Homework Help: Intro to Thermodynamics

  1. Dec 2, 2015 #1
    1. The problem statement, all variables and given/known data
    My lecture notes says that Work is the transfer of energy by means of a force acting on an object/body. What about heat energy? Does work also need to be done to transfer heat energy from hot object to cold object? Say if i drop a hot metal into room temp water. The metal gets colder and heat energy is transferred from metal to water which gets warmer. Does the metal do work on the water to transfer the heat energy?

    2. Relevant equations

    3. The attempt at a solution
  2. jcsd
  3. Dec 2, 2015 #2


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    Staff: Mentor

    No, different forms of energy get transferred in different ways.
  4. Dec 2, 2015 #3
    In the example that you gave, the transfer of heat is occurring on the molecular scale, by molecules with higher kinetic energy interacting with molecules with lower kinetic energy, so that the kinetic energy of the faster molecules decreases and the kinetic energy of the slower molecules increases. So it is not the same thing as work (which typically occurs macroscopically), and is typically the result of externally applied force.

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