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Math Help - Exponential Decay/and growth question involving half life.

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    Exponential Decay/and growth question involving half life.

    A 200 gram sample of compound XYZ has a half life of 304 hours.


    a.) state the decay/growth factor.
    b.) write an exponential equation that models this scenario.
    c.) Calculate how many grams of the sample will be left after 60 days to the nearest 100th of a gram.

    Please solve and explain. I have a quiz on this tomorrow.
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    Re: Exponential Decay/and growth question involving half life.

    Quote Originally Posted by Nabilrahman16 View Post
    A 200 gram sample of compound XYZ has a half life of 304 hours.


    a.) state the decay/growth factor.
    b.) write an exponential equation that models this scenario.
    c.) Calculate how many grams of the sample will be left after 60 days to the nearest 100th of a gram.

    Please solve and explain. I have a quiz on this tomorrow.
    two ways to go about this (y in grams, t in days) ...


    y = 200\left(\frac{1}{2}\right)^{k_1 \cdot t}

    100 = 200\left(\frac{1}{2}\right)^{k_1 \cdot \frac{38}{3}}

    solve for k_1 and you have your decay function.

    or ...

    y = 200e^{k_2 \cdot t}

    100 = 200e^{k_2 \cdot \frac{38}{3}}

    solve for k_2, same idea.
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