Respuesta :
Answer:
(a)[tex]N(t)=Noe^{kt}[/tex]
(b)5,832 Mosquitoes
(c)5 days
Step-by-step explanation:
(a)Given an original amount [tex]N_o[/tex] at t=0. The population of the colony with a growth rate [tex]k \neq 0[/tex], where k is a constant is given as:
[tex]N(t)=Noe^{kt}[/tex]
(b)If [tex]N_o=1000[/tex] and the population after 1 day, N(1)=1800
Then, from our model:
N(1)=1800
[tex]1800=1000e^{k}\\$Divide both sides by 1000\\e^{k}=1.8\\$Take the natural logarithm of both sides\\k=ln(1.8)[/tex]
Therefore, our model is:
[tex]N(t)=1000e^{t*ln(1.8)}\\N(t)=1000\cdot1.8^t[/tex]
In 3 days time
[tex]N(3)=1000\cdot1.8^3=5832[/tex]
The population of mosquitoes in 3 days time will be approximately 5832.
(c)If the population N(t)=20,000,we want to determine how many days it takes to attain that value.
From our model
[tex]N(t)=1000\cdot1.8^t\\20000=1000\cdot1.8^t\\$Divide both sides by 1000\\20=1.8^t\\$Convert to logarithm form\\Log_{1.8}20=t\\\frac{Log 20}{Log 1.8}=t\\ t=5.097\approx 5\; days[/tex]
In approximately 5 days, the population of mosquitoes will be 20,000.
Answer:
a) N(t) = Noe^kt
b) 5832mosquitoes
c) Approximately 5years
Step-by-step explanation:
If he rate of growth is equal the number of population present in a given time, we have:
dN/dt ∝ N
N is the number of population.
dN/dt = kN
k is the constant of proportionality
dN = kNdt
On separating the variables
dN/N = kdt
Integrating both sides of the equation, we have
∫dN/N = k∫dt
ln(N/No) = kt
Taking exp of both sides
e^ln(N/No) = e^kt
N/No = e^kt
N = Noe^kt
N(t) = Noe^kt
No is the original amount of population
t is the time in days
b) If there are 1000 mosquitoes initially and there are 1800 after 1 day,
N = 1800, No = 1000 at t = 1
1800 = 1000e^k(1)
1800/1000 = e^k
e^k = 1.8
Taking ln of both sides
lne^k = ln1.8
k = ln 1.8
k = 0.5878
To get the size of the colony after 3 days,
N(t) = 1000e^0.5878(3)
N(3) = 1000e^1.7634
N(3) = 1000×5.832
N(3) = 5832
The size if the colony after 3years is 5,832mosquitoes
c) To determine how long is it until there are 20,000 mosquitoes?
N(t) = Noe^kt
20,000 = 1000e^(0.5878)t
20,000/1,000 = e^0.5878t
20 = e^0.59t
ln20 = lne^0.5878t
ln 20 = 0.5878t
t = ln20/0.5878
t = 5.07years
It will take 5years until there are 20,000mosquitoes