Homework Help: calculus

Posted by Mackenzie on Thursday, April 12, 2012 at 1:04pm.

a radiotactive isotope lose 1/5 of its atoms in a sample decay after 14 years. find the half life.

calculus - Reiny, Thursday, April 12, 2012 at 1:11pm
if k is the half-life time, then

.8 = 1 (1/2)^(14/k)
log .8 = (14/k)(log .5)
14/k = log.8/log.5
k/14 = log.5/log.8
k = 14(log.5)/log.8 = 43.48
calculus - mackenzie, Thursday, April 12, 2012 at 1:12pm
thanks :D

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