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What is heat? what is kinetic energy?

  1. Nov 23, 2006 #1
    This may be a very stupid question but I've got no scientific background so stick with me. When talking at the level of atoms or atomic particles, what is meant by the notion of heat "transferring" between particles? People often use language that suggests heat is a thing or a kind of particle in itself. Is this literal or is heat better understood as a kind of effect particles have on each other? Whichever case is true, how do we know?

    The same thing applies to kentic energy - when one particle causes another to move, is something literally being exchanged between them?
  2. jcsd
  3. Nov 23, 2006 #2
    kinetic energy is a measure of the movement of an object, and heat is a measure of the random movement of an object.

    When two gases (initially at different temperatures) come together, the molecules literally collide with one another (which naturally tends to slow the more "energetic" molecule whilst suddenly speeding up the slower one a bit) until the whole volume has a uniform temperature.
  4. Nov 23, 2006 #3


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    Heat is the energy transferred from one object or substance to another due to a temperature difference. Kinetic energy is the energy a particle has due to its motion. Temperature is a measure of the average kinetic energy of the molecules or atoms an item or substance. As explained above, when two substances come together at different temperatures the kinetic energy is transfered from one substance to the other by the molecules or atoms colliding with each other. When they collide their average kinetic energy changes (because the molceules or atoms motion is affected by collisions) and this change in energy as I said above is what we call heat. So in summary heat isn't really something like a particle its just the transfer of energy from a hot thing to a colder thing.
  5. Nov 23, 2006 #4


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    What is being exchanged when a billiards ball crashes into another?
  6. Dec 6, 2006 #5


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    do you mean momentum?
  7. Dec 8, 2006 #6
    Thanks for all your replies! :eek:)
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