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Homework Help: Involved problem

  1. Oct 3, 2005 #1
    Energy Conservation Question

    here is a problem i need help getting started on:

    A 670kg meteorite composed of aluminum far from the earth has a temperature of -15C and moves with a speed of 14km/s relative to earth.
    As it crashes, assume that the resulting additional internal energy is shared equally between the meteor and the planet and that all of the material of the meteor rises to the same final temperature. Find this temperature.

    assume that the specific heat of liquid and gaseous aluminum is 1170 J/kg*C.

    No idea how to begin this although i am reminded not to forget about gravitational potential energy,
    thanks for some help on this one
    Last edited: Oct 4, 2005
  2. jcsd
  3. Oct 3, 2005 #2
    no help on this....
  4. Oct 4, 2005 #3


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    Science Advisor
    Homework Helper

    E = KE + PE
  5. Oct 4, 2005 #4
    right i know this is to be used but i dont know how to set up the initial and final energies. and also the wording about the energy being equally shared.

    can i get some more clarification on how to set these equations up.
  6. Oct 4, 2005 #5
    i really need some help with this one....
  7. Oct 5, 2005 #6
    no one can help ??
  8. Oct 5, 2005 #7

    Doc Al

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    Staff: Mentor

    What's the KE of the meteor when it hits earth? (It falls from "infinitely" far away to the surface of the earth. What's the change in gravitational PE?)

    Assume half of that energy remains in the meteor. You have the specific heat and the mass of the meteor; calculate the temperature change.
  9. Oct 5, 2005 #8
    Remember that initial energy is equal to final energy by the law of conservation of energy and that change in K+ change in U+change in Q = 0 as well, where U is potential energy, Q is thermal energy and K is kinetic energy.

    Hope that helps some :P
  10. Feb 5, 2012 #9
    Could someone please explain why the meteor's gravitational potential energy is converted to heat after the collision? I understand why the meteor's kinetic energy is converted to heat; after all, it's moving very quickly and then stops. That kinetic energy must go somewhere! But why is there any change in the meteor's gravitational potential energy from right before to right after the meteor strikes the Earth?
  11. Feb 7, 2012 #10
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