Respuesta :
Answer:
a) k = 0.00012491389
b) The Shroud of Turin was 755 years old at the time of this data.
Step-by-step explanation:
(a) Find the value of the constant k in the differential equation C' = -kC.
First we find the differential equation, by separation of variables. So
[tex]\int \frac{C^{\prime}}{C} dt = -\int k dt[/tex]
So
[tex]\ln{C} = -kt + K[/tex]
In which K is the constant of integration, representing the initial amount of substance. So
[tex]C(t) = C(0)e^{-kt}[/tex]
Half-life of 5549 years.
This means that [tex]C(5549) = 0.5C(0)[/tex]. We use this to find k. So
[tex]C(t) = C(0)e^{-kt}[/tex]
[tex]0.5C(0) = C(0)e^{-5549k}[/tex]
[tex]e^{-5549k} = 0.5[/tex]
[tex]\ln{e^{-5549k}} = \ln{0.5}[/tex]
[tex]-5549k = \ln{0.5}[/tex]
[tex]k = -\frac{\ln{0.5}}{5549}[/tex]
[tex]k = 0.00012491389[/tex]
So
[tex]C(t) = C(0)e^{-0.00012491389t}[/tex]
(b) In 1988 three teams of scientists found that the Shroud of Turin, which was reputed to be the burial cloth of Jesus, contained 91% of the amount of carbon-14 contained in freshly made cloth of the same material. How old was the Shroud of Turin at the time of this data?
This is t for which [tex]C(t) = 0.91C(0)[/tex]
So
[tex]C(t) = C(0)e^{-0.00012491389t}[/tex]
[tex]0.91C(0) = C(0)e^{-0.00012491389t}[/tex]
[tex]e^{-0.00012491389t} = 0.91[/tex]
[tex]\ln{e^{-0.00012491389t}} = \ln{0.91}[/tex]
[tex]-0.00012491389t = \ln{0.91}[/tex]
[tex]t = -\frac{\ln{0.91}}{0.00012491389}[/tex]
[tex]t = 755[/tex]
The Shroud of Turin was 755 years old at the time of this data.
