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Homework Help: Laplace of a Differential Equation

  1. Jul 19, 2009 #1
    I'm trying to solve the problems from this project:


    I already did problem # 1, and now I'm trying to solve problem # 2, which will help me to solve problem # 3.

    Solve the differential equation using the Laplace Transform:


    Knowing that


    So, what I did was that I plugged in the 2nd equation into the 1st equation, took the Laplace...and I got http://i27.tinypic.com/34glqbq.jpg"

    I'm stuck here because I don't know what to do with the T(0) and the S's ...

    I appreciate any help, thank you!
    Last edited by a moderator: Apr 24, 2017
  2. jcsd
  3. Jul 19, 2009 #2


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    One of the things you have written in your solution is "kT= 4.93". Where did you get that from? T is the dependent variable. kT is not a constant.
  4. Jul 21, 2009 #3
    Because T = 85 and K = .058. But something that I noticed that I might have wrong is that the time and temperatures are variables, so at a given time the temperature is going to be something, and at another time something else. Thus, I should keep the equations with the variables without plugging in any number so I can have an equation in which to plug in any time and temperature that I want from the table in problem 3.
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