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Thread: Half life problem...

  1. #1
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    Half life problem...

    The half-life of carbon-14 is 5600 years. If a piece of charcoal made from the wood of a tree shows only 67%
    of the carbon-14 expected in living matter, when did the tree die?
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  2. #2
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    Re: Half life problem...

    Pe^{kt} = \dfrac{P}{2} when t = 5600. Solve for k.

    Pe^{kt} = .67P when you plug in the value for k you got above. Solve for t.
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  3. #3
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    Re: Half life problem...

    Is k the 67%?
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  4. #4
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    Re: Half life problem...

    No. The .67 is 67%.
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  5. #5
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    Re: Half life problem...

    What is K then?
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  6. #6
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    Re: Half life problem...

    P = starting weight of the carbon-14
    k = constant of exponential decay for carbon-14 - can be found by solving the first formula I gave.
    t = time in years
    Last edited by SlipEternal; Dec 6th 2017 at 11:46 AM.
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