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You have a sample of a certain radioactive substance. After two days, thirty percent of the sample has decayed. What is the hal...Asked by math
You have a sample of a certain radioactive substance. After two days, thirty percent of the sample has decayed. What is the half-life of the material and how much will have decayed after a week?
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Answered by
Scott
100% - 30% = (1/2)^(2 / h)
log(.7) = (2 / h) log(1/2)
h = 2 log(1/2) / log(.7)
(after a week) = (1/2)^(7 / h)
log(.7) = (2 / h) log(1/2)
h = 2 log(1/2) / log(.7)
(after a week) = (1/2)^(7 / h)