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Thermodynamics freezer problem

  1. Nov 12, 2013 #1
    1. What volume of water at 0oC can a freezer make into ice cubes in 1.0 hour, if the coefficient of performance of the cooling unit is 7.0 and the power input is 1.0 kilowatt?

    2. C.O.P.=QL/W

    3. I found QL by using the above formula, which gave me 700J. Next I used Q=ml (l=333000j/kg) to find the mass which is where I got .002 kg (I'm pretty sure that this is where I made my mistake.) Next I know to use the formula for density to divide the mass by the density of water (1 x 103. Can somebody point out where I made a mistake, or if my thinking is wrong?
    Last edited: Nov 12, 2013
  2. jcsd
  3. Nov 12, 2013 #2


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    How do you 700J for QL ? Shouldn't it be 7J.
  4. Nov 12, 2013 #3


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    How many J/s are in 1 KW?
  5. Nov 12, 2013 #4
    Sorry, I figured out the problem (1000J/s in 1 KW instead of 100...,) but don't know how to close the thread (if possible.) Thanks for the responses though!
  6. Nov 13, 2013 #5


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    Only Administrators can close threads, so don't worry.
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