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September 1, 2014

September 1, 2014

Posted by **lala** on Tuesday, April 13, 2010 at 7:43pm.

a)Determine the half life of the substance

- Calculus -
**Reiny**, Tuesday, April 13, 2010 at 8:34pmFrom the equation we can see that the original amount was 100 units

So we want to know when that amount becomes 50

50 = 100(1.2)^-t

.5 = 1.2^-t

log(.5)= log(1.2^-t)

log(.5)= -tlog(1.2)

-t = log(.5)/log(1.2)

= -3.8

so t = 3.8 years is the half-life time

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