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Writing equation for integration regarding rate of change

  1. Jan 4, 2010 #1

    An object with temperature 26 degrees Celsius is placed in water with constant temperature of 90 degrees Celsius. If the temperature of the object rises to 70 degrees Celsius in five minutes, what will be the temperature after 10 minutes?

    I thought of using Newtons law of cooling d(temp)/d(t) = -k(constant of proportionality) (temp(object)-temp(surrounding medium)) but have read on the internet that it only describes transfer of heat from object to water not the other way around.

    Any ideas would be appreciated
  2. jcsd
  3. Jan 5, 2010 #2
    Well, if the object transfers some amount of heat to water, then you can say that the water transfers the same amount with opposite sign to the object,
    And all you need to do is to add a minus sign in from of the derivative.
    (I think so)
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