A hiker in Africa discovers a skull that contains 51% of its original amount of C-14.
N=Noe^-kt
No=initial amount of C-14(at time t=0)
N=amount of C-14 at time t
t=time, in years
k=0.0001
pleassse help im being timed
!!!!

Question

A hiker in Africa discovers a skull that contains 51% of its original amount of C-14.
N=Noe^-kt
No=initial amount of C-14(at time t=0)
N=amount of C-14 at time t
t=time, in years
k=0.0001
pleassse help im being timed
!!!!

anonymous · Answer

$$.51=e^{-.0001t}$$
$$\ln(.51)=-.0001t$$
$$t=\frac{ln(.51)}{-.0001}$$
$$t=6733.45$$ rounded

anonymous · Answer

i assume the question was "how old is it?"

anonymous · Answer

yess it was !!
thank you soo muchh!!! i have 4 more questions left if i need your help, can you please help me out?

anonymous · Answer

it was wrongg

mertsj · Answer

@satellite   When you're done here, go down three questions

anonymous · Answer

why was it wrong?  wasn't the question "how old?"

anonymous · Answer

maybe needed more decimal places but i am sure it is right, so long as k = .0001 as you wrote

anonymous · Answer

or maybe fewer decimal places since it is time in years

anonymous · Answer

yes it was
idk its timed so i cant go backk, but its okay 
can you help with another one?

anonymous · Answer

sure

anonymous · Answer

but apparently that didn't work so well

anonymous · Answer

a 18 gram sample of a substance thats used to detect explosives has a k-value of 0.1226 find the substance's half life, in days round your answer to the nearest tenth