Question 151243
 
In the formula A=I^ekt, A is the amount of radioactive material remaining from an initial amount I at a given time t and k is a negative constant determined by the nature of the material. 
An artifact is discovered at a certain site. 
If it has 53% of the carbon of the carbon-14 it originally contained, what is the approximate age of the artifact? (carbon-14 decays at the rate of 0.0125% annually.) Round to the nearest year.
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0.53I = Ie^(-0.000125t)
0.52 = e^(-0.000125t)
Take the natural log to get:
-0.000125t = ln(0.52)
t = 5231.41
rounded down t = 5231 years.
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Cheers,
Stan H.