A given bacteria culture initially contains 2000 bacteria and doubles every half hour. The number of bacteria p at a given time t is given by the formula p(t)=2000e^kt for some constant k. (You will need to find k to answer the following)A) find the size of the bacterial population after 20 minutes. B) find the size of the bacterial population after 6 hours.

Respuesta :

Now, we know that the culture initially contains 2000 bacteria and that it doubles every half hour. Assuming that the time t is in hours, this would mean that

[tex]p(0.5)=4000=2000e^{0.5k}[/tex]

Solving for k,

[tex]\begin{gathered} 4000=2000e^{0.5k} \\ \rightarrow2=e^{0.5k} \\ \rightarrow\log (2)=\log (e^{0.5k}) \\ \rightarrow\log (2)=0.5k\log (e) \\ \rightarrow k=\frac{\log (2)}{0.5} \\ \\ \Rightarrow k=2\log (2) \end{gathered}[/tex]

This way, we would have that:

[tex]p(t)=2000e^{2\log (2)\cdot t}[/tex]

A)

20 minutes is 1/3 of an hour. This way,

[tex]\begin{gathered} p(\frac{1}{3})=2000e^{2\log (2)\cdot\frac{1}{3}} \\ \\ \Rightarrow p(\frac{1}{3})=3174.80 \end{gathered}[/tex]

Thereby, the bacterial population after 20 minutes is 3,174.80

B)

[tex]\begin{gathered} p(6)=2000e^{2\log (2)\cdot6} \\ \Rightarrow p(6)=8192000 \end{gathered}[/tex]

Thereby, the bacterial population after 6 hours is 8,192,000