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

A rhombus is graphed
on the set of axes below.

Answers

Answer:

Step-by-step explanation:

reflection over y-axis

Option A is correct, 180 degree rotation counter clockwise about the origin is transformation which would carry the rhombus onto itself.

We need to consider the properties of a rhombus and how each transformation affects its shape and orientation.

A rhombus is a quadrilateral with all four sides of equal length. It also has opposite angles that are congruent. Based on this information, we can analyze each transformation option:

180-degree rotation counterclockwise about the origin is a transformation would preserve the shape and size of the rhombus since a 180-degree rotation does not change the lengths of the sides or the angles.

Therefore, it is a possible transformation that carries the rhombus onto itself.

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How would I unrationalize this fraction?
I am trying to find the cotangent in simplest form

Answers

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[tex] \cot(teetha) = - 1[/tex]

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The cotangent in simplest form is -1.

What is trigonometry?

Trigonometry is mainly concerned with specific functions of angles and their application to calculations. Trigonometry deals with the study of the relationship between the sides of a triangle (right-angled triangle) and its angles.

For the given situation,

cos θ = √2 / 2

We know that from trigonometric ratio,

[tex]cos \theta = \frac{Adjacent}{Hypotenuse}[/tex] , [tex]cot \theta = \frac{Adjacent }{ Opposite }[/tex]

So, the adjacent side = √2 and the hypotenuse side = 2.

The other side of the right triangle can be found by Pythagoras theorem,

[tex]hypotenuse^{2}=adjacent^{2}+opposite^{2}[/tex]

⇒ [tex]2^{2}=(\sqrt{2} )^{2} +opposite^{2}[/tex]

⇒ [tex]opposite^{2} = 4-2[/tex]

⇒ [tex]opposite = \sqrt{2}[/tex]

Thus, [tex]cot \theta = \frac{\sqrt{2} }{\sqrt{2} }[/tex]

⇒ [tex]cot \theta = 1[/tex]

Since cot θ < 0, [tex]cot \theta = - 1[/tex]

Hence we can conclude that the cotangent in simplest form is -1.

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Rewrite the following expression performing the subtraction.
(5c² - 3c + 9) - (2c²+ 8c - 3)
a) What did you need to distribute to the second polynomial to rewrite?

Perform subtraction. Then, answer:

b) How many terms? in the simplified expression

c) What is the leading coefficient of the simplified expression?

d) What is the degree of the simplified expression?

Answers

Answer:

a) [tex]3c^2-11c+12[/tex]

b) 3 terms in simplified expression

c) 3 is leading coefficient

d) 2 is the degree of simplified expression

Step-by-step explanation:

We need to perform subtraction of [tex](5c^2 - 3c + 9) - (2c^2+ 8c - 3)[/tex]

a) What did you need to distribute to the second polynomial to rewrite?

We need to multiply - sign with the terms inside the bracket.

Perform subtraction. Then, answer:

[tex](5c^2 - 3c + 9) - (2c^2+ 8c - 3)\\=5c^2 - 3c + 9 - 2c^2- 8c +3\\Combining \ like \ terms\\=5c^2-2c^2-3c-8c+9+3\\=3c^2-11c+12[/tex]

b) How many terms in the simplified expression?

There are 3 terms in the simplified solution [tex]3c^2-11c+12[/tex]

c) What is the leading coefficient of the simplified expression?

The leading coefficient is the coefficient with highest degree. The highest degree is 2 so, leading coefficient is 3

d) What is the degree of the simplified expression?

The highest degree is considered as the degree of simplified expression. In our case [tex]3c^2-11c+12[/tex] the highest degree is 2

Joey built a model sailboat that is similar to his real sailboat. The triangular sail on
his real boat has a base of 25 feet. If the height of the sail on his model boat is 12
inches and the base is 15 inches, what is the height of the sail on his real boat?​

Answers

Answer:

31.25

Step-by-step explanation:

25/12=2.083333

15 x 2.0833333=31.24999999995

round up to get 31.25

The height of the sail on his real boat is 20 feet.

We require the height of the sail on the real boat, H.

Let h be the height of sail on the model boat = 12 inches, B = base of sail on the real boat = 25 feet and b = base of sail on model boat = 15 inches.

By similar triangles,

H/h = B/b

H = Bh/b

Substituting the values of the variables into the equation, we have

H = Bh/b

H = 25 feet × 12 inches/15 inches

H = 25 feet × 4/5

H = 5 feet × 4

H = 20 feet

So, the height of the sail on his real boat is 20 feet.

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What is the solution of 2.4x+2.6=17

Answers

Answer:

x=6

Step-by-step explanation:

the answer should be x=6

How to do this question plz answer ​

Answers

Answer:

a. 9 sides

b. 18 sides

c. 24 sides

d. 30 sides

Step-by-step explanation:

We can use the equation 180(n-2), which n is the number of sides to find the answer.

a. 180(n-2)=1260

n-2=7

n=9

b. 180(n-2)=2880

n-2=16

n=18

c. 180(n-2)=3960

n-2=22

n=24

d. 180(n-2)=5040

n-2=28

n=30

Answer:

a) 9 sides

b) 18 sides

c) 24 sides

d) 30 sides

Step-by-step explanation:

sum of interior angles = (n - 2) * 180

where n is the number of sides

a) 1260

(n - 2) * 180 = 1260

(n - 2) = 1260/180

(n - 2) = 7

n = 7 + 2

n =  9

b) 2880

(n - 2) * 180 = 2880

(n - 2) = 2880/180

(n - 2) = 16

n = 16 + 2

n =  18

c) 3960

(n - 2) * 180 = 3960

(n - 2) = 3960/180

(n - 2) = 22

n = 22 + 2

n = 24

d) 5040

(n - 2) * 180 = 5040

(n - 2) = 5040/180

(n - 2) = 28

n = 28 + 2

n = 30

Which set of number is only made up of integers?
Negative 2 and StartFraction 4 Over 7 EndFraction, 0, Two-thirds, 4.6, 24
–7.6, 0, 4.ModifyingAbove 2 with bar, 16, 56
–33.3, –24, 1, 2 , 3
–23, –7, 5, 9, 190

Answers

Answer:

It is D (-23, -7, 5, 9, 190)

Step-by-step explanation:

:)

Multiply. Write your answer as a fraction in simplest form.

2/15 x 9

Answers

The answer is 6/5!! Hope this helped! <3

The value of the fraction is 6/5

What is an Equation?

Equations are mathematical statements with two algebraic expressions flanking the equals (=) sign on either side.

It demonstrates the equality of the relationship between the expressions printed on the left and right sides.

Coefficients, variables, operators, constants, terms, expressions, and the equal to sign are some of the components of an equation. The "=" sign and terms on both sides must always be present when writing an equation.

Given data ,

Let the number be = A

Now , the equation is expressed as

A = ( 2/15 ) x 9

On simplifying the equation , we get

A = 18/15

Dividing by 3 on the numerator and denominator , we get

A = 6/5

Therefore , the fraction in simplest form is 6/5

Hence , The value of the fraction is 6/5

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PLEASE HELP!! I have asked this many times with no answers I really need help.
What is the direction, y-intercept, and zeroes of f(x) = 4x^2 + 10x + 12.

Answers

I think to find the y-intercept, substitute 0 for x and sole for y. Y- intercepts (0, -12). The roots (zeroes) are the value where the graph intersects the x-axis. To find the the zeroes, replace y with 0 and solve for x. x = 3, -4. I’m sorry if this is wrong.

The direction of f(x) = 4x² + 10x + 12 is in upward direction.

y intercept of the f(x) is (0,, 12).

And number of zeros in f(x) is 2, at x = -5/4 + (√23 / 4)i  and  -5/4 - (√23 / 4)i.

What is function?

Function is a combination of different types of variable and constants in which for the different values of x the value of function y is unique.

The given function is,

f(x) = 4x² + 10x + 12.

The coefficient of x² is 4 which is positive, therefore, the graph is in the upward direction.

To find y intercept of the function,

Substitute x = 0, in the function,

f(x) = y = 4 (0)² + 10 (0) + 12

y = 12

The y intercept of the function is (0, 12).

To find the number of zeros, Substitute f(x) = 0,

Implies that,

4x² + 10x + 12 = 0

The values of x for the given quadratic equation are,

x =-5/4 + (√23 / 4)i and x =-5/4 - (√23 / 4)i

The number of zeros is two at -5/4 + (√23 / 4)i  and  -5/4 - (√23 / 4)i.

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help again:)!
Mr. Phuong stayed in a hotel room for 2 nights that cost $210. The hotel room tax rate is 12%. What is the total cost for the hotel room?

Answers

Answer:

$235.2

Step-by-step explanation:

$210 * (100%+12%)

= $210 * 112%

= $210 * 1.12

= $235.2

Hope this helped!

Answer:

The final answer is $470.40.

Step-by-step explanation:

210 x 2 = $420

To find the final price including tax, we must find 12% of $420.

420 x 0.12 = $50.4

Now, we must finalize the price by adding the tax to the price without tax.

$420 + $50.4 = $470.40

Therefore, the final cost for the hotel room is $470.40.

Hope this helps you out! :)

If you are making a scale drawing of a giraffe that is 6m tall, and the height of the giraffe in your drawing is 3cm, what is the scale of the drawing? Thank you and please explain how you obtained your answer.

Answers

Answer:

The scale would be 200

Step-by-step explanation:

If your giraffe is 3 cm and the scale drawing of the giraffe is 6m, in one meter, there are 100 cm, and 6/2=3 you multiply 2 by the 100 cm in the meter which gives you 200. You could also say 6m divided by 3cm which would also give you 200 or 600/300=200.

Write 36 as a Product of is prine
numbers
Write the factors in order, from smallest
to largest
36

Answers

Answer:

Step-by-step explanation:

Factors of 36 = 1 2 3 4 6 9 12 18 36

the Prime Factors of 36 are: 2, 2, 3, 3.

This is the answer

Answer:

36 = 2*2*3*3

or

2^2 * 3^2

Step-by-step explanation:

Break 36 into prime factors

36 = 6*6  

Since 6 isn't a prime number, factor 6

36 = 2*3   * 2*3

2 and 3 are prime numbers

In order from smallest to largest

36 = 2*2*3*3

or as exponents

36 = 2^2 * 3^2

Analyze the graph below by answering the questions. Describe the slope (+, - , change in values etc.) and what is the Y-intercept? How do you know?

Answers

Answer:

Step-by-step explanation:

The y-intercept is 3.

I know this because when x is 0 that is where the y-intercept is :)

Solve the system of equations using the substitution method (solving for x and y intercepts). Please give graphing points.
x+y=5
2x-y=-2
WILL GIVE BRAINLIEST​

Answers

Answer:

(x, y) = (1, 4)

Step-by-step explanation:

Given:  x+y=5 and 2x-y=-2

Solve for y and x

x+y=5; solve for y

y = 5 - x; substitute into other equation

2x-y= -2

2x - (5 - x) = -2

2x - 5 + x = -2; combine x's

3x - 5 = -2; add 5 to both sides

3x =3; divide by 3

x = 1; use this to solve for y

x+y=5

1 + y = 5; subtract 1 from both sides

y = 4

(x, y) = (1, 4)

Liam and Sam shared a chocolate bar. Liam ate 3/5 and Sam ate 4/10. Who ate more? How much more?

Answers

Liam ate 6/10, so 2/10 more.

Answer:

liam ate more . he ate 1/5 parts more

In the figure, a||b , and both lines are intersected by transversal t. Complete the statements to prove that ∠2 and ∠8 are supplementary angles.
Menu Options
m∠2 = m∠7 ( )
m∠7 + m∠8 = 180° ( )

Answers

Answer:

Step-by-step explanation:

m∠2 ≅ m∠7 [Alternate exterior angles]

m∠7 + m∠8 = 180° [Linear pair theorem]

m∠2 + m∠8 = 180° [Substitution property]

∠2 and ∠8 are supplementary [Definition of supplementary angles]

can u help me with my math

Answers

1b think

I am not sure

is 3x-2>1 a strict inequality

Answers

Answer:

Inequalities involving the symbol '>' or '<' are called strict inequalities.

Step-by-step explanation:

Hope this helped!

What is 480 divided by 60

Answers

Answer:

8

Step-by-step explanation:

The given number 480 divided by 60 equals 8.

The division process involves successive subtraction of the divisor from the dividend until the remainder becomes less than the divisor.

To 480 divided by 60, to perform this division by dividing 480 by 60, resulting in a quotient of 8.

Division is an arithmetic operation that separates a number into equal groups, in this case, 480 is divided into 60 groups of equal size, and each group contains 8 items.

Dividing 480 by 60 can also be represented as 480 ÷ 60 = 8.

Hence, divide the given number 480 by 60 is equal to 8.

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what is the perimeter of this figure? (3.14 for pi)**round ur answer to the nearest whole number

Answers

nearest is 3.2 that is with whole bumber

Can someone help me with part b on this question please?

Answers

9514 1404 393

Answer:

  12.0 cm

Step-by-step explanation:

The Pythagorean theorem applies:

  (12 cm)² +b² = (17 cm)²

  b² = (289 -144) cm² = 145 cm²

  b = √145 cm ≈ 12.04 cm

  b ≈ 12.0 cm . . . . rounded to 1 decimal place

When graphing inequalities, where can the solutions be found?

Answers

Solutions will be located in the shaded region. Since this is a “less than” problem, ordered pairs on the boundary line are not included in the solution set. These values are located in the shaded region, so are solutions. (When substituted into the inequality x–y<3.

When solving systems of inequalities, the solutions are the regions where all the inequalities are true and will be represented by the intersection of the shaded areas.

What is inequality?

Inequality is defined as mathematical statements that have a minimum of two terms containing variables or numbers that are not equal.

When graphing inequalities, the solutions can be found on the side of the number line or the coordinate plane where the inequality is true.

For example, if the inequality is x > 3, the solutions would be all the values of x that are greater than 3. These solutions would be represented by shading the area to the right of line x = 3 on the coordinate plane.

Similarly, if the inequality is y < 2, the solutions would be all the values of y that are less than 2. These solutions would be represented by shading the area below the line y = 2 on the coordinate plane.

It's important to note that when solving systems of inequalities, the solutions are the regions where all the inequalities are true and will be represented by the intersection of the shaded areas.

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Find the improper fraction that is equivalent to eight and five sixths

Answers

Answer:

53/6

Step-by-step explanation:

What is 400,000 in scientific notation?
O A) 40 x 104
OB) 400 x 103
OC) 4 x 106
OD) 4 x 105

Answers

Answer:

4 x 10⁵

so that i think will be OD)

Uh some math question..

Luis purchased 24 purple

plants and 8 pink plants.

He wants to plant them in

equal groups in his garden.

What is the largest number

of groups, he can make?

Answers

Answer: 8 groups is the largest number of groups he can make

2/18 x 16
answer fast !!!!!!!!!!!!!!

Answers

36/18

12/6

6/3


Answer is 2 :/

Simplify this expression using the distributive property.

3.1(x + 1) + 4(x – 2.3)

What is the expression in its simplest form?
3.1x + 3.1 + 4x – 9.2
0.9x + 9.2
7.1x – 6.1
12.4x + 6.1

Answers

Answer:

7.1x−6.1

Step-by-step explanation:

Distribute:

=(3.1)(x)+(3.1)(1)+(4)(x)+(4)(−2.3)

=3.1x+3.1+4x+−9.2

Combine Like Terms:

=3.1x+3.1+4x+−9.2

=(3.1x+4x)+(3.1+−9.2)

=7.1x+−6.1

Answer:

7.1x - 6.1

Step-by-step explanation:

nancy has x coins. Bill has 9 coins fewer than five times the number of coins nancy has. Write and simplify an expression for the total number of coins and have.

Answers

Answer:

5x-9

Step-by-step explanation:

If Bill has 9 coins less then 5 times Nancy's coins, the number of his coins is 5x-9.

It Snowed 2.91 inches in January, and it
snowed 6.76 inches in February. How
much did it snow altogether?

Answers

Answer:

9.67 inches altogether

Step-by-step explanation:

2.91 + 6.76 = 9.67

2.91

+6.76

--------------

 9.67

this is the correctanswer

given g (x) =-5x-4, find g (x) = (1)

Answers

Answer:

The answer and work is both located in the screenshot provided!

Step-by-step explanation:

Hoped this helped!

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