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Plutonium-240 decays according to the function where Q represents the quantity remaining after t years and k is the decay constant, 0.00011... How long will it take 24 grams of plutonium-240 to decay to 20 grams?

User Buddie
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2 Answers

7 votes
It will take 1,657.4 years.
User StaWho
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5 votes

Answer:

1657.47 years

Explanation:

Let's find the answer by using the decay formula:


Q=q*e^(-kt) where:

Q=quantity remaining after 't' years

q=initial amount

k=decay constant

t=time in years

Using the information provided by the problem we have:


20=24*e^(-0.00011t)


ln(20/24)/(-0.00011)=t


1657.47=t

In conclusion, it will take 1657.47 years.

User Scott Kronheim
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5.0k points