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if the rate for radioactive decay for a substance is r=-.0063 and time is being measured in days how do you find the half-life of the substance to the nearest hour?

  • math -

    Do you mean
    A(t) = Ao e^-(.0063 t) ????
    If so then
    1 = 2 e^-(.0063 t)
    .5 = e^-(.0063 t)
    ln .5 = -(.0063 t)
    -.69315 = -(.0063 t)
    t = 110.02 days which is about 110 days and one hour

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