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Homework Help: Specific Heat Capacity Question

  1. Mar 30, 2009 #1
    1. The problem statement, all variables and given/known data
    How much milk at 11 degrees Celcius was added to 0.16 kg of coffee at 91 degrees Celcius if the final temperature is 76.8 degrees Celcius?

    2. Relevant equations
    Well my teacher explained how to rearrange cm∆T = cm∆T to somehow come up with an equation to solve for the final temperature: Tf = T1 * m1 + T2 * m2 / (m1 + m2) How would I rearrange that to solve for one of the masses?

    3. The attempt at a solution
    No idea :(
  2. jcsd
  3. Mar 30, 2009 #2


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    Homework Helper

    I think you are missing a parentheses.

    Tf = (T1 * m1 + T2 * m2) / (m1 + m2)

    You want to consider the rather aptly named weighted average to determine your answer. Remember though that temperatures need to be in Kelvin.

    As to solving for a mass, it's your only unknown. Think Nike: Just do it.
  4. Mar 30, 2009 #3
    I'm not too sure I catch your drift.
  5. Mar 30, 2009 #4


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    Homework Helper

    Just plug in the numbers and solve.
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