# half life

• September 3rd 2007, 08:24 PM
bungy189
half life
I have the function A(t) with its differential equation of dA/dt= -kA
and the solution as a function: A(t)= Ao e^-kt.

I need to find the values of Ao and k in the equation A(t) before i
can continue with the rest of the question.

I think i've found the values for k but not 100% but have no idea

i found k= 1.2092x 10^-4
• September 3rd 2007, 08:37 PM
topsquark
Quote:

Originally Posted by bungy189
I have the function A(t) with its differential equation of dA/dt= -kA
and the solution as a function: A(t)= Ao e^-kt.

I need to find the values of Ao and k in the equation A(t) before i
can continue with the rest of the question.

I think i've found the values for k but not 100% but have no idea

i found k= 1.2092x 10^-4

Your k value is correct (well, I get $k = ln(2)/5730 \approx 1.2097 \times 10^{-4}$.)
The physical meaning of $A_0$ is the amount of C-14 present at time 0. You can't determine that from the information you have given us.