## anonymous 5 years ago A wooden artifact from an ancient tomb contains 30 percent of the carbon-14 that is present in living trees. How long ago was the artifact made? (The half-life of carbon-14 is 5730 years.) Your answer is ? years.

1. anonymous

formula is$Q=Q_0(\frac{1}{2})^{\frac{t}{5700}}$

2. anonymous

so you need to solve $.30=(\frac{1}{2})^{\frac{t}{5700}}$ for t

3. anonymous

take the log $ln(.3)=\frac{t}{5700}ln(\frac{1}{2})$ solve for t to get $t=5700\frac{ln(.3)}{ln(.5)}$

4. anonymous

now use a calculator

5. anonymous

i get 9900