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Homework Help: A temp change of 20 degrees C

  1. Jun 7, 2003 #1


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    A temp change of 20 degrees C corresponds to a temp change of

    68degrees F

    i got this one wrong? whats up with that???
    Last edited by a moderator: Feb 5, 2013
  2. jcsd
  3. Jun 7, 2003 #2


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    Gold Member

    Well, its asking for a change...

    20 deg C=68 deg F...but...

    Lets say the change in C is from 0 to 20, then the change in F is from 32 to 68, giving your answer of (68-32)=36
  4. Jun 8, 2003 #3


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    Science Advisor

    Water freezes at 32 degrees F= 0 degrees C
    Water boils at 212 degrees F= 100 degrees C
    so that 212-32= 190 degrees F spans as much as 100 degrees C so each degree C corresponds to 190/100= 1.9 degrees F.

    A change of 20 degrees C corresponds to a change of 20(1.9)= 38 degrees F.

    (Or, you could have argued that 20 degrees C is 1/5 of the way from freezing to boiling and so corresponds to (212-32)/5= 190/5= 38 degrees F.

    (Oh, by the way, a temperature of 20 degrees C is 70 degrees F, not 68. The general formula is F= 1.9C+ 32.
  5. Jun 8, 2003 #4


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    Thanks for the info Ivy and dav2008.
    BTW...9/5 = 1.8C + 32 not 1.9 and my answer of 68 degrees is right.


    Dx :wink:
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