Prehistoric cave paintings were discovered in a cave in France. The paint contained 3% of the original carbon-14. Use the exponential decay model for carbon-14, A=A0e^-0.000121t, to estimate the age of the paintings.


The painting area approximately __ years old.

Respuesta :

Answer:

The painting area is approximately 28980 years old.

Step-by-step explanation:

The model for the amount of carbon-14 after t years is given by:

[tex]A(t) = A(0)e^{-0.000121t}[/tex]

In which A(0) is the original amount.

The paint contained 3% of the original carbon-14.

This means that [tex]A(t) = 0.03A(0)[/tex]. This means that we have to find t.

[tex]A(t) = A(0)e^{-0.000121t}[/tex]

[tex]0.03A(0) = A(0)e^{-0.000121t}[/tex]

[tex]e^{-0.000121t} = 0.03[/tex]

[tex]\ln{e^{-0.000121t}} = \ln{0.03}[/tex]

[tex]-0.000121t = \ln{0.03}[/tex]

[tex]t = -\frac{\ln{0.03}}{0.000121}[/tex]

[tex]t = 28980[/tex]

The painting area is approximately 28980 years old.