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Understanding the use of a figure in thermodynamics.

  1. Dec 3, 2015 #1
    I came across an equation used in one of the forums from a few years ago.

    Found here: https://www.physicsforums.com/threads/calculate-how-long-it-will-take-for-the-ice-to-melt.531908/

    I am researching a similar topic into melting ice and using it as a cooling solution.

    However when i came across this equation everything was done correctly but a figure stuck out.

    Why is the value of water's "Lf = 3.35 × 105 J kg-1" when in all other areas of the internet it is valued at 334 j / g?

    I want to use this method to solve my own issue with a container but which value is correct for this equation?

    Any assistance is greatly appreciated.

    Thanks
    Michael
     
  2. jcsd
  3. Dec 3, 2015 #2

    Ken G

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    Gold Member

    Converting from "per kg" to "per g" means dividing by 1000. If you divide 3.35 times 105 by 1000, you get 335. Are you asking about the difference between 335 and 334? Sounds like a simple rounding difference.
     
  4. Dec 3, 2015 #3
    I see my error, yes it is a simple rounding difference. It just threw me off a first glance, its been a long night hehe! Problem solved!
     
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