Respuesta :

Given:

Initial number of bacteria = 3000

With a growth constant (k) of 2.8 per hour.

To find:

The number of hours it will take to be 15,000 bacteria.

Solution:

Let P(t) be the number of bacteria after t number of hours.

The exponential growth model (continuously) is:

[tex]P(t)=P_0e^{kt}[/tex]

Where, [tex]P_0[/tex] is the initial value, k is the growth constant and t is the number of years.

Putting [tex]P(t)=15000,P_0=3000, k=2.8[/tex] in the above formula, we get

[tex]15000=3000e^{2.8t}[/tex]

[tex]\dfrac{15000}{3000}=e^{2.8t}[/tex]

[tex]5=e^{2.8t}[/tex]

Taking ln on both sides, we get

[tex]\ln 5=\ln e^{2.8t}[/tex]

[tex]1.609438=2.8t[/tex]                  [tex][\because \ln e^x=x][/tex]

[tex]\dfrac{1.609438}{2.8}=t[/tex]

[tex]0.574799=t[/tex]

[tex]t\approx 0.575[/tex]

Therefore, the number of bacteria will be 15,000 after 0.575 hours.