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Heat energy

Discussion in 'Homework Help' started by bthistle, Feb 16, 2008.

  1. bthistle

    Thread Starter New Member

    Feb 12, 2008
    6
    0
    Question
    How much energy is required to raise the temperature of 5kg of water by 32C?

    My attempt
    Q = m * c * dT
    = 5kg * 4187 J/(kg C) * 32C
    = 669920 J

    am i doing it right?
    thanks
    bill
     
  2. jpanhalt

    Expert

    Jan 18, 2008
    7,683
    1,889
    Looks pretty good tome. BTW, watch your significant figures. I presume the question meant 5.000Kg, 32.00°C, ETC. If not, 5 Kg is only 1 significant figure.

    Where it may matter is the conversion from calories to Joules. You have 4 significant figures there, so the answer should be 669900.
    (If you used 6 significant figures, as I found on the Internet, the 4th digit is different.)
    John
     
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