a piece of charcoal is found to contain 30% of the carbon 14 that it originally had. when did the tree die from which the charcoal came? use 5600 years as the half-life of carbon 14.
A(t)=Aoe^kt k

Question

a piece of charcoal is found to contain 30% of the carbon 14 that it originally had. when did the tree die from which the charcoal came? use 5600 years as the half-life of carbon 14.
A(t)=Aoe^kt                    k<0

anonymous · Answer

0.3 = e^(kt) where k is given by  0.5 = e^(5600k)
Solve for t

anonymous · Answer

i get a funky answer when i try and solve for k....

anonymous · Answer

What do you get...

anonymous · Answer

-1.237......x10^-4

anonymous · Answer

Yup, that's about right

anonymous · Answer

oh really? i thought it was supposed to be cleaner than that...

anonymous · Answer

so that i could plug it back in to get t

anonymous · Answer

yea, my answer is still way off from the back of the book