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Homework Help: Heat transfer from cooling lava

  1. Dec 4, 2013 #1
    1. The problem statement, all variables and given/known data
    The world's most active volcanos, such as the Kilauea volcano in Hawaii, can disgorge about 5 ✕ 105 m3 of 1000°C lava per day. What is the rate of heat transfer out of the earth by convection if this lava has a density of 2800 kg/m3 and eventually cools to 32°C? Assume that the specific heat of lava is the same as that of granite. Answer in MW.

    2. Relevant equations
    P = Q/t

    3. The attempt at a solution

    Solved the density equation for mass (m=1.4*10E9kg)
    Solved for Q (Q=1.07*10E15J)
    Solved for P (P=1.24*10E10W or 12400MW)

    Followed an example from book, what am I missing
  2. jcsd
  3. Dec 5, 2013 #2


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    I take it your answer has been marked wrong. I get 12390MW, so I would probably have been marked wrong too.
  4. Dec 5, 2013 #3
    Thanks for trying
  5. Dec 5, 2013 #4
    What about the heat of solidification?
  6. Dec 5, 2013 #5
    Thanks chestermiller been searching for fusion number for granite found 100cal/gm can anyone verify
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