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Homework Help: Thermodynamics - Melting of Ice

  1. Jan 12, 2009 #1
    1. The problem statement, all variables and given/known data

    The density of ice is 0·92×103 kg m−3 and its latent heat of fusion is 3·3×105 J kg−1.

    Estimate the melting temperature of the ice at the bottom of a glacier which is 100m deep.

    2. Relevant equations

    L = Tc(S2 - S1)

    3. The attempt at a solution

    (S2 - S1) = 1208.8

    I then tried to get somewhere with this, but kept going around in circles and couldn't work out how to incorporate the fact it's at the bottom of the glacier.

    I'm guessing it's something to do with the pressure of the ice above, and worked out this was

    p = F/A = 9×105

    but, couldn't figure out what to do with it from there. Any help would be appreciated.
    Last edited: Jan 12, 2009
  2. jcsd
  3. Jan 12, 2009 #2
    Numerical results, unless they are pure numbers should be presented with units.
    Are we speaking of 1208.8 sausages and 9×10e5 lumps of sugar?

    A little bit of internet searching will tell you that a pressure of 100 atmospheres will lower the melting point of ice (generally 0°C) by about 1°C, that is to say not a lot.
    Here's the reference

    So how much pressure is there at the bottom of a 100m thick glacier? Pressure in a medium like this is calculated as height*density (which gives us force per unit area). What does this mean approximately in terms of atmospheres (don't neglect the atmosphere itself).
    Last edited by a moderator: Apr 24, 2017
  4. Jan 12, 2009 #3


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    This may be a simple typo. I suspect either m should be cm here, or the 10-3 should be 10+3
  5. Jan 12, 2009 #4
    Sorry, that should indeed be +3
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