A quantity P obeys the exponential growth law P(t)=e5t (t in years).
At what time t0 is P=15? Use yr for years. t0=?
At what time t1 is P=20? Use yr for years. t1= ?
What is the doubling time for P? Use yr for years. The doubling time is ?

Respuesta :

Answer:

the time at which P =15 is [tex]{t_o = 0.54161 \ years}[/tex]

the time at which P =20 is [tex]{t_1 = 0.59914 \ years}[/tex]

the doubling time [tex]{t = 0.138629 \ years}[/tex]

Step-by-step explanation:

From the information we are being provided with:

The quantity P i.e [tex]P(t) = e ^{5t}[/tex]

In order to determine the time at which P = 15, we have the following:

[tex]t= t_o[/tex]    when P = 15

∴ [tex]e^{5t_o} = 15[/tex]

[tex]5t_o= In (15)[/tex]

[tex]t_o = \dfrac{1}{5}In 15[/tex]

[tex]t_o = \dfrac{1}{5} \times 2.70805[/tex]

[tex]{t_o = 0.54161 \ years}[/tex]

Hence, the time at which P =15 is [tex]{t_o = 0.54161 \ years}[/tex]

In order to determine the time at which P = 20, we have the following:

[tex]t= t_1[/tex]    when P = 20

∴ [tex]e^{5t_1} = 20[/tex]

[tex]5t_1= In (20)[/tex]

[tex]t_1= \dfrac{1}{5}In (20)[/tex]

[tex]t_1 = \dfrac{1}{5} \times 2.9957[/tex]

[tex]{t_1 = 0.59914 \ years}[/tex]

Hence, the time at which P =20 is [tex]{t_1 = 0.59914 \ years}[/tex]

The doubling time at t = 0, mean P = 2

∴ [tex]e^{5t} = 2[/tex]

[tex]5t= In (2)[/tex]

[tex]t= \dfrac{1}{5}In(2)[/tex]

[tex]t = \dfrac{1}{5} \times0.693147[/tex]

[tex]{t = 0.138629 \ years}[/tex]

Hence, the doubling time [tex]{t = 0.138629 \ years}[/tex]