SOLUTION: A scientist begins with 100 milligrams of a radioactive substance that decays exponentially. After 35 hours, 50 mg of the substance remains. How many milligrams will remain after

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Question 1137504: A scientist begins with 100 milligrams of a radioactive substance that decays exponentially. After 35 hours, 50 mg of the substance remains. How many milligrams will remain after 54 hours?
Answer by greenestamps(13208) About Me  (Show Source):
You can put this solution on YOUR website!


Half the original amount remains after 35 hours, so the half life is 35 hours.

Then the fraction remaining after t hours is

%281%2F2%29%5E%28t%2F35%29

After 54 hours the fraction remaining is

%281%2F2%29%5E%2854%2F35%29+=+0.3432 to 4 decimal places.

ANSWER: The amount remaining after 54 hours is approximately 34.32mg.