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March 2, 2015

March 2, 2015

Posted by **Beth** on Saturday, October 11, 2008 at 10:12am.

A(t)= Ae^(-t/r)

where A(t) is the amount (of substance) after time t, A is the initial amount at time t=0 and r is the decay time.

The fall time is defined as the time in which A(t) falls from 90% to 10% of its initial value. Find the relationship between the fall time of an exponential decay and r.

- Physics -
**bobpursley**, Saturday, October 11, 2008 at 11:53amI will start it off

.9=e^t1/r

ln .9 = t1/r

likewise..

ln .1=t2/r

tfall=t2-t1, well you do that...

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