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Thread: Radioactive Decay

  1. October 12th 2009, 12:31 PM #1
    Royster123
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    Radioactive Decay

    If Forty percent of a radioactive substance decays in five years. By what percent does the substance decay each year?
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  2. October 12th 2009, 12:51 PM #2
    e^(i*pi)
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    Quote Originally Posted by Royster123 View Post
    If Forty percent of a radioactive substance decays in five years. By what percent does the substance decay each year?
    Exponential Decay: N(t) = N_0e^{-\lambda t}

    0.6 = 1e^{-40\lambda}

    \lambda = -\frac{1}{40}ln(0.6)

    <br /> N(t) = 1e^{-\left(-\frac{1}{40}ln(0.6)\right) \times 1)}
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