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Did I set up my differential equation correctly?

  1. Dec 15, 2014 #1
    1. The problem statement, all variables and given/known data
    Shown in attachment

    The problem has been modified. All inputs and outputs are 5 gal/min. Pure water enters tank 1.
    2. Relevant equations
    System of equations

    3. The attempt at a solution
    Included on attachment.

    Attached Files:

  2. jcsd
  3. Dec 15, 2014 #2
    Tank 1 has 10 gal/min going in and only 5 gal/min coming out...it'll all end in tears (whether the briny sort or the ripping sort, only time will tell). Maybe the T1->T2 pipe should be 10 gal/min.
  4. Dec 15, 2014 #3
    I'm going by what the teacher says.
  5. Dec 15, 2014 #4


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    Judging from part E, the total volume in each tank is supposed to be constant. Neither the original data nor the modified data achieve that.
    I suggest you put in unknowns for the rate of flow from outside the system into tank1 and the rate of return from tank2 to tank1. The other two flow rates can then be deduced. solve the question in terms of those unknowns. When you get the right data, you can just plug it in to your equations.
  6. Dec 16, 2014 #5
    And if the teacher says black is white, zebras suddenly become horses.

    The answer to your thread title question is "no".
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