SOLUTION: Ok this involves using growth and decay equations it says "a material decays at a rate of 1.1% per year .if you start with 250 grams of the material, in how many years will there b
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-> SOLUTION: Ok this involves using growth and decay equations it says "a material decays at a rate of 1.1% per year .if you start with 250 grams of the material, in how many years will there b
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Question 706104: Ok this involves using growth and decay equations it says "a material decays at a rate of 1.1% per year .if you start with 250 grams of the material, in how many years will there be 100 grams remaining?" And it wants me to find the right equation to start off with can you help me? Answer by nerdybill(7384) (Show Source):
You can put this solution on YOUR website! Ok this involves using growth and decay equations it says "a material decays at a rate of 1.1% per year .if you start with 250 grams of the material, in how many years will there be 100 grams remaining?" And it wants me to find the right equation to start off with can you help me?
.
The exponential growth/decay equation is:
A = Pe^(rt)
where
A is amount after time t (100)
P is initial amount (250 grams)
r is rate (-.011) (r<0 for decay)
t is time (what we're looking for)
.
100 = 250e^(-.011t)
100/250 = e^(-.011t)
2/5 = e^(-.011t)
ln(2/5) = -.011t
ln(2/5)/(-.011) = t
83.3 years = t
