SOLUTION: An anthropologist finds there is so little remaining Carbon-14 in a prehistoric bone that instruments cannot measure it. This means that there is less than 0.5% of the amount of Ca

Algebra.Com
Question 475305: An anthropologist finds there is so little remaining Carbon-14 in a prehistoric bone that instruments cannot measure it. This means that there is less than 0.5% of the amount of Carbon-14 the bones would have contained when the person was alive. How long ago did the person die? Round your answer to the nearest thousand. (22,000, etc)
Answer by ankor@dixie-net.com(22740)   (Show Source): You can put this solution on YOUR website!
An anthropologist finds there is so little remaining Carbon-14 in a prehistoric bone that instruments cannot measure it.
This means that there is less than 0.5% of the amount of Carbon-14 the bones would have contained when the person was alive.
How long ago did the person die? Round your answer to the nearest thousand. (22,000, etc)
:
The half life formula
A = Ao*2^(-t/h)
Where
A = remaining amt after t yrs
Ao = initial amt
t = time in yrs
h = half-life of substance
:
The generally accepted half-life for Carbon 14 = 5730 yrs
We can assume the initial amt = 1, the resulting amt =.005
:
2^(-t/5730) = .005
using nat logs
ln(2) = ln(.005)
=
= -7.6438562
t = -5730 * -7.6438562
t = 43,800 yrs

RELATED QUESTIONS

How do I set this up so I can solve it, it's a word proble. An anthropologist studying... (answered by stanbon)
An anthropologist finds bone that her instruments measure it as 0.824% of the amount of... (answered by solver91311)
An anthropologist finds bone that her instruments measure it as 0.364% of the amount of... (answered by josgarithmetic)
An anthropologist finds bone that her instruments measure it as 0.146% of the amount of... (answered by ankor@dixie-net.com)
3.An anthropologist finds bone that her instruments measure it as 0.824% of the amount... (answered by fractalier)
2. An anthropologist finds bone that her instruments measure it as 0.146% of the amount... (answered by fractalier)
2.1. An anthropologist finds bone that her instruments measure it as 0.717% of the... (answered by josgarithmetic)
6.An anthropologist finds bone that her instruments measure it as 0.177% of the amount... (answered by jim_thompson5910)
An anthropologist finds bone that her instruments measure it as 0.556% of the amount of... (answered by Alan3354)