SOLUTION: This problem is about Radioactive decay...I am having a hard time solving the problem below..Any help will be appreciated. Thank you..Could you show me the steps please? the bo

Algebra ->  Logarithm Solvers, Trainers and Word Problems -> SOLUTION: This problem is about Radioactive decay...I am having a hard time solving the problem below..Any help will be appreciated. Thank you..Could you show me the steps please? the bo      Log On


   



Question 378592: This problem is about Radioactive decay...I am having a hard time solving the problem below..Any help will be appreciated. Thank you..Could you show me the steps please?
the bones of a math professor contain 98% of the original amount of carbon 14 (decay rate =0.012% per year) how long ago did he die?

Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
the bones of a math professor contain 98% of the original amount of carbon 14 (decay rate =0.012% per year) how long ago did he die?
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Note 0.012% = 0.012/100 = 0.00012
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A(t) = Ao(1-0.00012)^t
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0.98*Ao = Ao(0.999880)^t
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0.999880^t = 0.98
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Take the log to get:
t*log0.999880 = log0.98
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t = [log0.98]/[log0.999880]
t = 168.35 years
Round up to He died 168.35 years ago.
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Cheers,
Stan H.