Suppose that a large mixing tank initially holds 100 gallons of water in which 50 pounds of salt have been dissolved. Another brine solution is pumped into the tank at a rate of 3 gal/min, and when the solution is well stirred, it is then pumped out at a slower rate of 2 gal/min. If the concentration of the solution entering is 4 lb/gal, determine a differential equation (in lb/min) for the amount of salt A(t) (in lb) in the tank at time t > 0. (Use A for A(t).)

Answers

Answer 1

Answer:

dA/dt = 12 - 2A/(100 + t)

Step-by-step explanation:

The differential equation of this problem is;

dA/dt = R_in - R_out

Where;

R_in is the rate at which salt enters

R_out is the rate at which salt exits

R_in = (concentration of salt in inflow) × (input rate of brine)

We are given;

Concentration of salt in inflow = 4 lb/gal

Input rate of brine = 3 gal/min

Thus;

R_in = 4 × 3 = 12 lb/min

Due to the fact that solution is pumped out at a slower rate, thus it is accumulating at the rate of (3 - 2)gal/min = 1 gal/min

So, after t minutes, there will be (100 + t) gallons in the tank

Therefore;

R_out = (concentration of salt in outflow) × (output rate of brine)

R_out = [A(t)/(100 + t)]lb/gal × 2 gal/min

R_out = 2A(t)/(100 + t) lb/min

So, we substitute the values of R_in and R_out into the Differential equation to get;

dA/dt = 12 - 2A(t)/(100 + t)

Since we are to use A foe A(t), thus the Differential equation is now;

dA/dt = 12 - 2A/(100 + t)


Related Questions

Two forces of magnitudes 16 and 20 pounds are acting on an object. The bearings of the forces are N75E and S20E (that is, 75∘ east of north and 20∘ east of south), respectively. How many degrees east of south is the resultant force? (Round to two decimal places and do not enter the ∘ symbol.)

Answers

Answer:

20.58

Step-by-step explanation:

Force A = 16 pounds

direction = N75E = 75° in the first quadrant

Force B = 20 pounds

direction = S20E = 180° - 20° = 160° in the fourth quadrants

we resolve the forces into their x and y resultant forces.

For the y axis forces,

-(16 x sin 75°) + (20 x sin 160°) = Fy

-15.45 + 6.84 = Fy

Fy = -8.61 N

For the x axis forces'

(16 x cos 75°) + (20 x cos 160°) = Fx

-4.14 - 18.79 = Fx

Fx = -22.93 N

Resultant force = [tex]\sqrt{(Fx)^{2} + (Fy)^{2} }[/tex] =  [tex]\sqrt{(-8.61)^{2} + (-22.93)^{2} }[/tex]

Resultant force = 24.49 N

angle made by the resultant force is,

∅ = [tex]tan^{-1}[/tex] [tex]\frac{Fy}{Fx}}[/tex]

∅  =  [tex]tan^{-1}[/tex] [tex]\frac{-8.61}{-22.93}}[/tex]

∅ =  [tex]tan^{-1}[/tex] 0.3755

∅ = 20.58

Express the following ratio in it’s simplest form.
25:30

Answers

Answer:

5/6

Step-by-step explanation:

Find the factor that divides both numbers...

25/5=5

30/5=6

5/6 is the simplified ratio

P.S. Please give me brainliest, i have only have two!

Answer:

1/3:1/4

Step-by-step explanation:

203/259

write in simplest form

2 hours to 45 seconds

Express ratio

15:1

simplest form

1/3:1/4

What is the measure of angle L in parallelogrami LMNO?
20°
30°
40°
50°

Answers

Answer:

40°

Step-by-step explanation:

2x = 3x - 20 add like terms

x = 20 and angle l is equal to 3x minus 20 so 3 × 20 - 20 = 40°

During the late 1980s and the early 1990s the Pepsi Challenge was in full swing. During the challenge, participants were asked to taste cola from both Coke and Pepsi. Once they had tasted both drinks, the participants were asked to report which was better tasting. The results indicated that participants found Pepsi products to be better tasting. What is the dependent variable in this study? coruse hero psyc 255

Answers

Answer:

Taste

Step-by-step explanation:

In the challenge, participants were asked to taste cola from both Coke and Pepsi. They were to give a report on which of the two drinks tasted better.

The taste reported by the participants is dependent on the type of cola taken (either Coke or Pepsi).

Therefore, the taste is the dependent variable while the types of cola are the independent variables.

5. The value of 25sqare -24sqare

Answers

Answer:

49

Step-by-step explanation:

25²-24²

625-576

=49

use calculator lah dehh

A baseball player comes up to bat 3 times during a league game. He either gets a hit or gets an out. What is the probability that the player gets 3 hits in the three bats ?

Answers

Answer:

Since there are 2 possibilities for each bat (hit or out), the amount of total possibilities is 2 * 2 * 2 = 8. There is only one possibility out of those eight that gives us three hits, therefore the probability is 1 / 8 or 0.125.

If a line crosses the y-axis at (0,1) and has a slope of 4/5 what is the equation of the line

Answers

Answer:

y = 4/5x + 1

Step-by-step explanation:

y = mx + b

m = slope

b = y-intercept

y = 4/5x + 1

Answer:4y-5x=5

Step-by-step explanation:

Simplify 4^3•4^5.
help asap !

Answers

Answer:

D

Step-by-step explanation:

when there are exponents with same bases multiplied by each other, keep the base and add the exponents

4^(3)+4^(5)=4^8

4^8 is D in this question

NOT SURE NEED HELP PLEASE​

Answers

Answer:

bh

6, 17

102

51

Step-by-step explanation:

Answer:

1/2 (bh)

1/2(17)(6)

51

Martin wants to use coordinate geometry to prove that the opposite sides of
a rectangle are congruent. He places parallelogram ABCD in the coordinate
plane so that A is (0,0), B is (a,0), Cis (a, b), and Dis (0, b).
What formula can he use to determine the distance from point D to point A?

Answers

Answer:

Option (B)

Step-by-step explanation:

Coordinates of the vertices of the rectangle were A(0, 0), B(a, 0), C(a, b) and D(0, b)

Formula to determine the distance between two points with the vertices (x, y) and (x', y') is,

d = [tex]\sqrt{(x-x')^2+(y-y')^2}[/tex]

For the length of AD,

AD = [tex]\sqrt{(0-0)^2+(b-0)^2}[/tex]

     = [tex]\sqrt{b^2}[/tex]

     = b

Therefore, Option (B) will be the answer.

Can someone plz help me solved this problem I need help ASAP plz help me! Will mark you as brainiest!

Answers

Answer:

-1, 1

13, 15

Step-by-step explanation:

x and x+2 are the integers

x*(x+2)= 7(x+x+2) -1x²+2x= 14x+14-1x² - 12x -13= 0

Roots of the quadratic equation are: -1 and 13.

So the integers pairs are: -1, 1 and 13, 15

A company makes candles in the shape of a right cone. The lateral surface of each candle is covered with paper for shipping and each candle also has a plastic circular base. Find the amount of paper needed to cover the lateral surface of each candle. Then find the total amount of paper and plastic needed for the candle. Round to the nearest tenth. Use 3.14 for π.

Answers

Answer:

If we have a cone-shape candle with r=2 cm and h=3 cm, then the amount of paper needed is 18.84 cm^2 and the amount of plastic needed is 12.56 cm^2.

Step-by-step explanation:

The question is incomplete: no numerical values for the dimensions of the cone are given.

A right cone is defined by the radius r of the base and the height h.

The base area is the area of a circle with radius r:

[tex]A_b=\pi r^2[/tex]

The lateral area is calculated as:

[tex]A_l=\pi \cdot r\cdot l[/tex]

As the values for r and h are not given, we will use an example with r=2 and h=3.

Then, the amount of paper needed is:

[tex]A_l=\pi \cdot r\cdot l=3.14\cdot (2\,cm)\cdot (3\, cm)=18.84\,cm^2[/tex]

The amount of plastic needed is:

[tex]A_b=\pi r^2=3.14\cdot (2\,cm)^2=3.14\cdot 4\,cm^2=12.56\,cm^2[/tex]

What is the value of -(3/4) to the power of -4

Answers

The answer would be -3 13/81 (simplified)

What is the range of the function in the table

X Y
1 2
2 4
3 3
4 2

A) (1,2,3,4)
B) (1,2) (2,4) (3,3) (4,2)
C) (1,2)
D) (2,3,4)

Answers

Answer:

D. (2, 3, 4)

Step-by-step explanation:

The range is the y values. The y values, in numerical order, range from 2 to 4. The 2s do not need to be repeated.

resuelve las siguientes ecuaciones tales que 0° ≤ x ≤ 360°
sen x=sen (π/2-x)
cos x + 2 sen x= 2
csc x = sec x
2 cos x * tan x -1 = 0
4 cos2 x = 3 - 4 cos x

Answers

Answer:

4cos=2X

X=3-4COS

X=-1

round 3, 942,588 to the nearest thousand

Answers

Answer:

3, 943,000

Step-by-step explanation:

3, 942,588

The 2 is in the thousands place

We look at the hundreds place

There is a 5, that means we round up

2 becomes a 3

3, 943,000

What’s the correct answer for this question?

Answers

Answer:

C:

Step-by-step explanation:

In a circle, the measure of an inscribed angle is half the measure of the central angle with the same intercepted arc

So

AQD = ARC AD/2

<AQD = 78/2

<AQD = 39°

Which rule represents the translation from he pre-image, ABCD, to the image, A’B’C’D’?

Answers

Answer:

Option (4)

Step-by-step explanation:

From the figure attached,

Quadrilateral ABCD has been translated to form an image A'B'C'D' by shifting 'a' units right and 'b' units up.

Let the rule for translation is,

(x, y) → (x + a, y + b)

Coordinates of point A is (-4, 4) and the coordinates of the image A' are (-2, 5).

So, (-4, 4) → [(-4 + 2), (4 + 1)]

Therefore, the translation can be represented by [tex]T_{2, 1}(x, y)[/tex] (shifted 2 units right and 1 unit up).

Option (4) will be the answer.

Answer:

T2,1(x,y)

Step-by-step explanation:

The Hartnett Corporation manufactures baseball bats with Pudge Rodriguez's autograph stamped on them. Each bat for $35 and has a variable cost of $22. there are $97,500 in fixed costs involved in the production process.
Find the sales (in units) needed to earn a profit of $300,000.

Answers

Answer:

Find the sales (in units) needed to earn a profit of $262,500

Step-by-step explanation:

hope this is helpful to you bro

1. Determine the value of 'p' in the equation 4p = 48

2. Simplify the fraction 60/144

3. What is the surface area of a cube with side lengths of 3cm?

Answers

1) sorry i don't know =(

2)- 5/12 is the simplified fraction for 60/144.

3)A=54cm²

Multiply or divide as indicated x^10/x^4

Answers

Answer:

X^6

Step-by-step explanation:

Peter, Gordon and Gavin share £36 in a ratio 2:1:1. How much money does each person get?

Answers

Answer:

Peter gets 18£

Gordon and Gavin each get 9£

Answer:

peter = 18 Gordon = 9 Gavin = 9

Step-by-step explanation:

2+1+1 = 4

36 div 4 = 9

2 times 9 = 18

1 times 9 = 9

which one of the following solids produces these two-dimensional shape when sliced horizontally?

Answers

Answer:

D

Step-by-step explanation:

The answer and how to solve it.

Answers

Answer:

B

Step-by-step explanation:

11. A square with sides
3/8
inch has a total area of:

Answers

Answer:

[tex](\frac{3}{8}\,in )^2=\frac{9}{64} \,in^2=0.140625\,\,i^2[/tex]

Step-by-step explanation:

Recall that the formula for the area of a square of side L is: [tex]Area=L^2[/tex]

Therefore, for this case:

[tex]Area=L^2\\Area = (\frac{3}{8} \,in)^2\\Area=\frac{9}{64} \,\,in^2\\Area=0.140625\,\,in^2[/tex]

A county real estate appraiser wants to develop a statistical model to predict the appraised value of houses in a section of the county called East Meadow. One of the many variables thought to be an important predictor of appraised value is the total number of rooms in the house. Consequently the appraiser decided to fit the simple linear regression model, ^y=β0+β1x , where y= the appraised value of the house (in thousands of dollars) and x= the number of rooms. Using data collected for a sample of n = 74 houses in East Meadow, the following results were obtained:

Answers

Answer:

Step-by-step explanation:

Hello!

The statistical model predicts the appraised value of houses in a section of the county East Meadow (Y) in relationship with the number of rooms of the house (X)

For a sample of n=64 houses the simple linear regression was estimated:

^Y= 74.80 + 24.93X

Range of X: 5 - 11

Range of Y: 160 - 300 ($ thousands of dollars)

Interpretation of the estimates of the y-intercept and the slope

y-intercept:

74.80 thousand dollars is the estimated average value of a house in a section of the county East Meadow when the house has zero rooms.

Slope:

24.93 [tex]\frac{thousand dollars}{rooms}[/tex] is the modification of the estimated average value of a house in a section of the county East Meadow when the number of rooms increases on one.

I hope this helps!

The function f(x)=2x2−x+4; f ( x ) = 2 x 2 − x + 4 is defined over the domain 0 ≤ x ≤ 3 Find the range of this function. A. 4 < f(x) < 7 B. 4 < f(x )< 19 C. 4 ≤ f(x) ≤ 19 D. 4 ≤ f(x) ≤ 25

Answers

Answer:

  C.  4 ≤ f(x) ≤ 19 . . . . . . best of bad answer choices

Step-by-step explanation:

When looking for the range of a function on an interval, one must check the function values at the ends of the interval, along with any local maxima or minima.

Here, the function values at the interval ends are ...

  f(0) = 4

  f(3) = 2·3² -3 +4 = 19

The axis of symmetry is located at ...

  x = -b/(2a) = -(-1)/(2(2)) = 1/4

This is a value in the interval, so will be the location of the minimum value of the function.

  f(1/4) = 2(1/4)² -1/4 +4 = 3.875

The range of f(x) on the interval [0, 3] is [3.875, 19]:

   3.875 ≤ f(x) ≤ 19

__

All of the answer choices are incorrect. Please discuss question this with your teacher.

Which of the following expressions represents "the sum of n and the sum of 8 and 6"? n(8 + 6) n + (8 + 6) (n + 6)8

Answers

the answer is n+(8+6)

Solve for x


There’s no options sorry ya’ll please answer I’m desperate

Answers

Answer & Step-by-step explanation:

The triangle shown is an isosceles triangles. Isosceles triangles have a pair of congruent angles which are found at the bottom. These angles are called the base angles. So, when you find the measurement of one of the base angles, then the other base angle will have the same measurement.

We can find the measurement of x by subtracting 130 from 180. We are doing this because all triangles have a sum measurement of 180°. After we do this, then we will divide that number by 2 to find the measurement of x.

180 - 130 = 50

Now, we divide 50 by 2.

50 ÷ 2 = 25

So, the measurement of x is 25°.

The histogram to the right represents the weights​ (in pounds) of members of a certain​ high-school debate team. What is the class​ width? What are the approximate lower and upper class limits of the first​ class? The class width is_______.

Answers

Answer:

Class width = 20

Approximate lower class limit of the first class = 110

Approximate Upper class limit of the first class = 119

Step-by-step Explanation:

The class width of the histogram attached below can be gotten by finding the difference between successive lower class limits.

Thus, class width = 130 - 110 = 20

The approximate lower class limit of the first class is the lowest score we have in the first class = 110

The approximate upper class limit of the first class is the closest highest score that fall within the first class and is below the lower limit of the second class. Thus approximate upper class limit of the first class = 129

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