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Homework Help: How could I find the rate of heat absorption?

  1. Feb 12, 2012 #1
    1. The problem statement, all variables and given/known data

    At what rate is a refrigerator absorbing heat if 2·15 kg of water at 21·5 °C is just frozen in 2·00 h?

    2. Relevant equations

    Q = mL
    Q = mcΔT

    3. The attempt at a solution

    Rate of Heat Absorbed = Q/t
    = mcΔT/t
    = (2.15*4.2*21.5)/(2*60*60)
    = 2.6*10^-2

    The actual answer should be 1·27x10^2 Js-1
    Last edited by a moderator: Feb 12, 2012
  2. jcsd
  3. Feb 12, 2012 #2


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    You calculated the rate to lower the temperature of the water from 21.5 C to 0 C. After you remove this heat, the water will still be liquid. How much more heat do you have to remove to turn it into ice?
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