SOLUTION: A certain radioactive element decays exponentially with a half-life of 5 hours. Find the time that has elapsed if a 50mg sample has decayed to 17 mg.
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-> SOLUTION: A certain radioactive element decays exponentially with a half-life of 5 hours. Find the time that has elapsed if a 50mg sample has decayed to 17 mg.
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Question 127753: A certain radioactive element decays exponentially with a half-life of 5 hours. Find the time that has elapsed if a 50mg sample has decayed to 17 mg. Answer by stanbon(75887) (Show Source):
You can put this solution on YOUR website! A certain radioactive element decays exponentially with a half-life of 5 hours. Find the time that has elapsed if a 50mg sample has decayed to 17 mg.
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A(t) = A(0)(1/2)^(t/5)
17 = 50 (1/2)^(t/5)
0.34 = (1/2)^(t/5)
Take the log of both sides to get:
(t/5)log(1/2) = log(0.34)
t/5 = 1.5564
t = 7.782 hours
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Cheers,
Stan H.
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