All i need help with is this please

A bacteria culture starts with 160 bacteria and grows at a rate proportional to its size. After 5 hours there will be 800 bacter

Leona [35]

Answer:

Step-by-step explanation:

Let the rate at which the bacteria grow be represented by the exponential equation

P(t) = P0e^kt

P(t) is the population of the bacteria after time t

P0 is the initial population

k is the constant of variation

t is the time

If the initial Population is 160 bacteria's, them the equation becomes;

P(t) = 160e^kt

b) if After 5 hours there will be 800 bacteria, this means

at t = 5 p(t) = 800

Substitute and get k

800 = 160e^5k

800/160 = e^5k

5 = e^5k

Apply ln to both sides

Ln5 = lne^5k

ln5 = 5k

k = ln5/5

k = 0.3219

Next is to calculate the population after 7hrs i.e at t = 7

P(7) = 160e^0.3219(7)

P(7) = 160e^2.2532

P(7) = 160(9.5181)

P(7) = 1522.9

Hence the population after 7houra will be approximately 1523populations

c) To calculate the time it will take the population to reach 2790

When p(t) = 2790, t = ?

2790 = 160e^0.3219t

2790/160 = e^0.3219t

17.4375 = e^0.3219t

ln17.4375 = lne^0.3219t

2.8587 = 0.3219t

t = 2.8587/0.3219

t = 8.88 hrs

Hence it will take approximately 9hrs for the population to reach 2790

7 0

3 years ago

Write a polynomial function that meets the given conditions. Answers may vary. Degree 2 polynomial with zeros of 2√ 13 and -2√13

MAVERICK [17]

Answer:

The polynomial function is $x^{2} - 52$

Step-by-step explanation:

A polynomial has roots $x_{1}, x_{2}$ such that $ax^{2} + bx + c = (x - x_{1})*(x - x_{2})$ .

In this problem:

The roots are $x_{1} = 2\sqrt{13}$ and $x_{2} = -2\sqrt{13}$

Then

$(x - 2\sqrt{13}) \times (x - (-2\sqrt{13})) = (x - 2\sqrt{13}) \times (x + 2\sqrt{13}) = x^{2} - 2x\sqrt{13} + 2x\sqrt{13} -(2\sqrt{13})^{2} = x^{2} - 52$

The polynomial function is $x^{2} - 52$

8 0

3 years ago

Find the center of mass of the wire that lies along the curve r and has density =4(1 sin4tcos4t)

dolphi86 [110]

The mass of the wire is found to be 40π√2 units.

To calculate the mass of the wire which runs along the curve r ( t ) with the density function δ=5.

The general formula is,

Mass = $\int_a^b \delta\left|r^{\prime}(t)\right| d t$

To find, we must differentiate this same given curve r ( t ) with respect to t to estimate |r'(t)|.

The given integration limits in this case are a = 0, b = 2π.

Now, as per the question;

The equation of the curve is given as;

r(t) = (4cost)i + (4sint)j + 4tk

Now, differentiate this same given curve r ( t ) with respect to t.

$\begin{aligned}\left|r^{\prime}(t)\right| &=\sqrt{(-4 \sin t)^2+(4 \cos t)^2+4^2} \\&=\sqrt{16 \sin ^2 t+16 \cos ^2 t+16} \\&=\sqrt{16\left(\sin t^2+\cos ^2 t\right)+16}\end{aligned}$

Further simplifying;

$\begin{aligned}&=\sqrt{16(1)+16} \\&=\sqrt{16+16} \\&=\sqrt{32} \\\left|r^{\prime}(t)\right| &=4 \sqrt{2}\end{aligned}$

Now, use integration to find the mass of the wire;

$\begin{aligned}&=\int_a^b \delta\left|r^{\prime}(t)\right| d t \\&=\int_0^{2 \pi} 54 \sqrt{2} d t \\&=20 \sqrt{2} \int_0^{2 \pi} d t \\&=20 \sqrt{2}[t]_0^{2 \pi} \\&=20 \sqrt{2}[2 \pi-0] \\&=40 \pi \sqrt{2}\end{aligned}$

Therefore, the mass of the wire is estimated as 40π√2 units.

To know more about density function, here

brainly.com/question/27846146

#SPJ4

The complete question is-

Find the mass of the wire that lies along the curve r and has density δ.

r(t) = (4cost)i + (4sint)j + 4tk, 0≤t≤2π; δ=5

5 0

1 year ago

Carissa has $250 in her checking account

exis [7]

Answer:

c

Step-by-step explanation:

8 0

3 years ago

Plz help what’s the answer

Maslowich

Answer:

a. 192 b.60 c. 184, 164, 350

Step-by-step explanation:

a.Total of males=88+104

b.Female, Anaerobic=156-96

c. aerobic= 88+96=184

anaerobic=104+60

total=192+158

8 0

3 years ago