Suppose there are two lakes located on a stream. Clean water flows into the first lake, then the water from the first lake flows into the second lake, and then water from the second lake flows further downstream. The in and out flow from each lake is 500 liters per hour. The first lake contains 100 thousand liters of water and the second lake contains 200 thousand liters of water. A truck with 500 kg of toxic substances crashes into the first lake. Assume that the water is being continually mixed perfectly by the stream.
a. Find the concentration of toxic substances as a function of time in both lakes.
b. When will the concentration in the first lake be below 0.001 kg per liter?
c. When will the concentration in the second lake be maximal?

Answers

Answer 1

Answer:

a.  For the first lake;

c = (m·t - 0.005·m·t²)/100000

For the second tank, we have;

c = m·t/200 - m·t²/80000

b. t ≈ 1.00505 hours

c. 200 hours

Step-by-step explanation:

The flow rate of water in and out of the lakes = 500 liters/hour

The volume of water in the first lake = 100 thousand liters

The volume of water in the second lake = 200 thousand liters

The mass of toxic substances that entered into the first lake =  500 kg

The concentration of toxic substance in the first lake = m₁/(100000)

Therefore, we have;

The quantity of fresh water supplied at t hours = 500 × t

The change

The change in the mass of the toxic substance with time is given as follows

dm/dt = (m - m/100000 × 500 × t)/100000

c = (m·t - 0.005·m·t²)/100000

For the second tank, we have;

c = m/100000 × 500 × t - (m/100000 × 500 × t)/200000 × 500 × t

Using an online tool, we have;

c = m·t/200 - m·t²/80000

b. When c < 0.001 kg per liter, we have m < 0.001 × 100000, which gives m < 100

Substituting gives;

0.001 = (100·t - 0.005·100·t²)/100000, solving with an online tool, gives;

t ≈ 1.00505 hours

c. For maximum concentration, we have;

c = m·t/200 - m·t²/80000

m/200000 = m·t/200 - m·t²/80000

1/200000 = t/200 - t²/80000

dc/dt = d(t/200 - t²/80000)/dt = 0

Solving with an online tool gives t = 200 hours


Related Questions

14
A canteen spends money on food and drink in the ratio of 29:3
In total, they spend £6496.
Find how much money they spend on drink.​

Answers

Answer:

Money spend on drink  = £ 609

Step-by-step explanation:

Food : drink = 29 : 3

Money spend on food = 29x

Money spend on drink = 3x

Total money spend = 29x + 3x = 32x

32x = £6496

   x = 6496/32

  x = £ 203

Money spend on drink = 3x = 3 * 203 = £ 609

Answer:

who knows the answer if u know the answer pls tell

evaluate (73)^2 using the identity (a+b)^2=a2+2ab+b^2

Answers

73^2 = 5329

There's no identity that can be used.

PLS GIVE BRAINLIEST

A farmer's market is selling peaches for $2.00 a pound. If you buy 2 pounds, you save 10% on each pound. How much does it cost to get 2 pounds of peaches?

Answers

Answer:3.6

0

Step-by-step explanation:

Because 10 percent of 1.00 is 0.10 and if you do 10 percent of 1.00 times two it is 20 percent of 2..00 which is 0.4

Solve for t in the equation

Answers

Answer:

t=1/5=0.2

Step-by-step explanation:

(5t+3)/4=1

5t+3=4

5t=1

t=1/5=0.2

Answer:

1/5

Step-by-step explanation:

5t+3/4=1

5t+3=1*4

5t+3=4

5t=4-3

5t=1

t=1/5

what is halfway between 5.3 and 5.4

Answers

Answer:

5.35

Step-by-step explanation:

5.31 5.32 5.33 5.34 5.35

The answer will be 5.35

Triangle P'Q'R is the image of PQR under a transformation

Answers

Answer:

what is your question

Step-by-step explanation:

Answer:

Step-by-step explanation:

there is no picture....

A pure green beetle is crossed with a pure brown beetle. All of the offspring are green. Which explanation below, correctly explains this phenomenon?

A.Green and brown are equally expressed so they are both dominant.


B.Green is more common than brown so more green genes are passed on.


C.The gene for green color is dominant over the gene for brown color.



D.The gene for brown color is dominant over the gene for green color.

Answers

Answer:

C.

The green color gene is more dominant over the gene for brown color.

Step-by-step explanation:

Whichever gene is dominant is the one that will be applied to the organism.

A builder made a scale drawing of a rectangular room. The drawing has a length of 12 ½ cenmeters and a width of 7 ¾ cenmeters. The actual room will have a length of 56 ¼ meters. What will be the area of the actual room?

Answers

Answer:

18 / 6 = 3

The scale is 1:3

3 * 4.5 = 13.5

13.5 * 18 = 243 square feet

The answer is 243 square feet.

Step-by-step explanation:

Hope this helped!

Write an equation in point -slope form with given information

slope is -5
point at (-3,8)

Answers

Answer:

Step-by-step explanation:

If we know the slope and a point, we can easily write it in point-slope form

[tex]y - y_1 = m(x-x_1)\\y - 8 = -5(x-(-3))\\y - 8 = -5(x+3)[/tex]

I need helppppppppp!!!!

Answers

I drew on the coordinates to help you visualize! :) When moving to the left the Y value stays the same however, the X would decrease by 5.

Which number line correctly shows –3 – 1.5?

Answers

Answer:

A

Step-by-step explanation:

The formula for the volume of a tetrahedron is given as v=sh. Rewrite the
equation so that the height is a function of the area of base and the volume (solve for
the height), then find the height when the area of base is 8 and the volume is 48.

Answers

Answer:

h = 6 units

Step-by-step explanation:

The formula for the volume of a tetrahedron is given as :

V = sh

Where

s is area of base and h is height

Put s = 8 and V = 48 to find h as follows :

[tex]h=\dfrac{V}{s}\\\\=\dfrac{48}{8}\\\\h=6[/tex]

So, the height of the tetrahedron is 6 units.

(I need to make sure)
Which pair of numbers has the greatest GCF?
A = 140 and 210
B = 130 and 390
C = 240 and 320
D = 550 and 880

Answers

i think it’s C not completely sure tho

Can you find the slope-intercept of the line? Thank you!

Answers

Answer:

y = x + 2

Step-by-step explanation:

The equation of a line in slope- intercept form is

y = mx + c ( m is the slope and c the y- intercept )

Calculate m using the slope formula

m = [tex]\frac{y_{2}-y_{1} }{x_{2}-x_{1} }[/tex]

with (x₁, y₁ ) = (- 2, 0) and (x₂, y₂ ) = (0, 2) ← 2 points on the line

m = [tex]\frac{2-0}{0+2}[/tex] = [tex]\frac{2}{2}[/tex] = 1

The line crosses the y- axis at (0, 2) ⇒ c = 2

y = x + 2 ← equation of line

Which of the following equations would have to be the second equation so that the system has no solutions?
A. y = -x
B. 9y = 6x
C. y = x - 4
D. 6x - 4y = 6

Answers

Answer:

I put 9y=6x

Step-by-step explanation:

I say this because I’ve put all points in on Desmos graph and this is the best answer choice to me dk if I’m right .

An antelope can run 152.5 miles in 2.5 hours. The average speed of the antelope 62 mi/hr

True
False

Answers

Answer:

Step-by-step explanation:

152.2 miles /2.5 hours= 60.88 mph so false.

check by 62 mph * 2.5 hours = 155 miles or more then what the antelope actually ran.

12x² + 8x = 0
What are the zeroes?

Answers

Answer:

The zeros are at 0 and -2/3

hcf and lcm of 120 and 180, shown your work

Answers

The HCM and LCM of 120 and 180 are 360.

What is HCF and LCM?

The Highest Common Factor (HCF) of two or more given numbers is the largest number that divides each of the given numbers without leaving any remainder. The Least Common Multiple (LCM) of two or more numbers is the smallest of the common multiples of those numbers.

Given are two numbers as -

120 and 180

We can write 120 and 180 as -

120 = 2 x 2 x 2 x 3 x 5

180 = 2 x 2 x 3 x 3 x 5

HCF of 120 and 180 will be equal to = 2 x 2 x 3 x 5 = 60

Now, we can find LCM using the formula -

LCM(a, b) = (a x b)/HCF(a, b)

LCM(a, b) = (120 x 180)/60

LCM(a, b) = 2 x 180 = 360

Therefore, the HCM and LCM of 120 and 180 are 360.

To solve more questions on HCF and LCM, visit the link below-

https://brainly.com/question/20739723

#SPJ2

how many times bigger is 2 times 10 to the 10th power than 150 million

Answers

Answer: 2 x 10^10 =20000000000

and 150,000,000 is 150 million so you subtract and you get

19,850,000,000

Step-by-step explanation:

index notation 3 x 7 x 7 x 7 x 7​

Answers

Answer:

7203

Step-by-step explanation:

sorry if I am wrong

Answer:

Step-by-step explanation:

3×7⁴

May it help

The vehicle's fuel efficiency is at least 35 miles per gallon.
Use f to represent the vehicle's fuel efficiency (in miles per gallon).

Answers

Answer:

f ≥ 35

Step-by-step explanation:

Took the test on Aleks, it was right! :)

HELP PLEASE ILL GIVE U 50 POINTS​

Answers

Answer:

6x^2+2x

Step-by-step explanation:

Answer:

area of rectangle=2x×(3x+1)=6x²+2x

ab (3a-5b) equals to?

Answers

Answer:

3a^2b-5ab^2

Step-by-step explanation:

Answer:

3a²b-5ab²

Step-by-step explanation:

Distribution method:

ab (3a-5b) = 3a²b-5ab²

The tables below represent different ratios of teaspoons of sugar to ounces of iced tea. Which table represents the greatest ratio of sugar-to-iced tea?

Answers

Answer:

Option (C)

Step-by-step explanation:

Option A.

Ratio of table spoons of sugar to ounces of iced tea = [tex]\frac{\text{Amount of sugar (in oz)}}{\text{Amount of ice tea (in oz)}}[/tex]

From the table attached,

Ratio = [tex]\frac{6}{24}[/tex]

         = 1 : 4

Option B.

Ratio of sugar to ounces of iced tea = [tex]\frac{3}{18}[/tex]

                                                            = 1 : 6

Option C.

Ratio of sugar to ounces of iced tea = [tex]\frac{1}{3}[/tex]

                                                            = 1 : 3

Option D.

Ratio of sugar to ounces of iced tea = [tex]\frac{7}{24}[/tex]

                                                            = 7 : 24

                                                            ≈ 1 : 3.43

Since, highest ratio means biggest fraction (with least denominator).

From the given options, biggest fraction is [tex]\frac{1}{3}[/tex].

Therefore, highest ratio of amount of sugar in (tsp) to number of ounces of ice tea is in Option (C).

4x/3+3=x-2
value of x ?​

Answers

Answer:

x = - 15

Step-by-step explanation:

Given

[tex]\frac{4x}{3}[/tex] + 3 = x - 2

Multiply through by 3 to clear the fraction

4x + 9 = 3x - 6 ( subtract 3x from both sides )

x + 9 = - 6 ( subtract 9 from both sides )

x = - 15

Step-by-step explanation:

find the LCM of 3 and 1 which is 3

then you have

4x/3 +3/1 =4x+9/3

now equate the above with x-2

4x+9/3=x-2

Cross multiply

3(x-2)=1(4x+9)

3x-6=4x+9

3x-4x=9+6

-x=15

x = -15

What is the image of (2,3)(2,3) after a reflection over the line y=-xy=−x?

Answers

Answer:

After the reflection over the line  y = -x, the image of the point is: (-3,-2)

Step-by-step explanation:

When a given point is reflected over a line the point only changes place but the distance between the point and the line remains same.

Let (x,y) be a point on the plane

and

y = -x be a line on the plane

When a point is reflected over a line y = -x , the coordinates of the point are exchanged which means x becomes y and y becomes x and both are negated

So (x,y) will become (-y,-x)

Given point is:

(2,3)

After the reflection over the line  y = -x, the image of the point is: (-3,-2)

Kevin ate 3 apples. This represents 20% of the bag of apples. How many apples were originally in the bag?

Answers

27 total apples in the bag
15 apples were in the bag. If 3 apples are 20%, you could multiply 3 by 5 and 20% by 5 to get 100%.

Use the equation to answer the question 12 equals 3x + 6 what is the value of x makes the equation true

Answers

X is equal to 2 because 3(2) is 6 and the remaining 6 is equal to 12 6+6=12
X=2

Identify the hypotenuse.

A. MN
B. LN​

Answers

Answer:

The hypotenuse is line segment MN.

Step-by-step explanation:

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The angle 90 degrees (also represented by the red line on angle L) always always is opposite to the hypotenuse. Since angle L is 90 degrees, it is opposite of the hypotenuse, which is MN.

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#teamtrees #WAP (Water And Plant)

10 Theo earned £16520 last year and spent 13% of his money on making home improvements.
Find how much money Theo spent on home improvements last year.
Give your answer to the nearest penny.
f
(2)​

Answers

Answer:

2147.60

Step-by-step explanation:

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