SOLUTION: Find the associated exponential decay or growth model. Q = 2,500 when t = 0; half-life = 5

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Question 903876: Find the associated exponential decay or growth model.
Q = 2,500 when t = 0; half-life = 5
Answer by josgarithmetic(39617) About Me  (Show Source):
You can put this solution on YOUR website!
Q=q%2Ae%5E%28kt%29 using q=2500, and I am using two variables differently than are you.

Your half-life information goes this way:
t for half life is t=5.
Q=(1/2)q, so form a more specific equation as:
1%2F2=1%2Ae%5E%28k%2A5%29
ln%281%2F2%29=ln%28e%5E%285k%29%29
5k%2A1=ln%281%2F2%29
k=%281%2F5%29ln%281%2F2%29
highlight%28k=-%281%2F5%29ln%282%29%29, for a decimal value of approximately -0.139.


Model to use, highlight%28Q=2500%2Ae%5E%28-0.139%2At%29%29.