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    The Half life of a waste material is 6 months.

    Show that the activity will decrease about 1000 in 5 years.
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    (Original post by joyoustele)
    The Half life of a waste material is 6 months.

    Show that the activity will decrease about 10000 in 5 years.

    Are you sure 10,000 is the correct answer?
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    (Original post by uberteknik)
    Are you sure 10,000 is the correct answer?
    sorry, it's 1,000
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    (Original post by joyoustele)
    sorry, it's 1,000
    OK.

    You can use the relationship:

    N_{t} = N_{t_{0}}(e^{\frac{-t}{\tau}})

    and

    t_{\frac{1}{2}} = \tau ln(2)

    where

    t = \textrm{total decay time}

    t_{\frac{1}{2}} = \textrm{half life}

    \tau = \textrm{decay time constant}
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    (Original post by uberteknik)
    OK.

    You can use the relationship:

    N_{t} = N_{t_{0}}(e^{\frac{-t}{\tau}})

    and

    t_{\frac{1}{2}} = \tau ln(2)

    where

    t = \textrm{total decay time}

    t_{\frac{1}{2}} = \textrm{half life}

    \tau = \textrm{decay time constant}
    Thanks, i managed to do it
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    (Original post by joyoustele)
    Thanks, i managed to do it
    You don't need to convert to seconds since it's the ratio of the times that are needed, just keep the time units the same. i.e. 6 months and 60 months (5 years).
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    (Original post by uberteknik)
    You don't need to convert to seconds since it's the ratio of the times that are needed, just keep the time units the same. i.e. 6 months and 60 months (5 years).
    oh. Okay. Thank you very much
 
 
 
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