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Math Help - solving a differential equation.

  1. #1
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    solving a differential equation.

    hi, how yould you go about solving an equation like this?

    dv/dt=12.2 - kv ?? help very appreciated thanks!
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  2. #2
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    it's separable.
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  3. #3
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    Quote Originally Posted by Krizalid View Post
    it's separable.
    no its not!!! you cant really separate them...
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  4. #4
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    it is as long as "k" doesn't depend of "t."
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  5. #5
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    Quote Originally Posted by Krizalid View Post
    it is as long as "k" doesn't depend of "t."
    sorry, but i really dont understand what your saying. can you please just show me a step further and help me out because i really am lost i would really appreciate it.
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  6. #6
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    \frac{dv}{12.2 - kv} = dt

    \frac{-k}{12.2 - kv} \, dv = -k \, dt

    integrate both sides ...
    Last edited by skeeter; May 13th 2010 at 01:53 PM. Reason: fixed typo
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  7. #7
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    Quote Originally Posted by skeeter View Post
    \frac{dv}{12.2 - kv} = dt

    \frac{-k}{12.2 - kv} = -k \, dt

    integrate both sides ...

    how come you just removed dv from the equation?

    and so whats the general solution? is it : v= (ae^-kt - 12.2)/-k ?????
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  8. #8
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    Quote Originally Posted by Yehia View Post
    how come you just removed dv from the equation?

    and so whats the general solution? is it : v= (ae^-kt - 12.2)/-k ?????
    didn't mean to "remove it" ... just a typo. it's fixed.
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