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3241004551 [841]
3 years ago
10

The mass of a radioactive substance follows a continuous exponential decay model, with a decay rate parameter of 1% per day. A s

ample of this radioactive substance has an initial mass of 2.5kg. Find the mass of the sample after five days.
Physics
1 answer:
Bumek [7]3 years ago
6 0

Answer:

2,38kg

Explanation:

Mass in function of time can be found by the formula: m_{(t)} =m_{0} e^{-kt}, where m_{0} is the initial mass, t is the time and k is a constant.

Given that a sample decay 1% per day, that means that after first day you have 99% of mass.

m_{(1)} =m_{0} e^{-k(1)}, but m_{(1)}=\frac{99m_{0} }{100}, so we have \frac{99m_{0} }{100}=m_{0}e^{-k}, then k=-ln(\frac{99}{100})=0.01

Now using k found we must to find m_{(5)}.

m_{(5)}=m_{0}e^{-(0.01)5}=2.5kge^{-0.05} =2.5x0.951=2.38kg

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Explanation:

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