A tank initially contains 100 gallons of brine with 10 lb of salt dissolved in it. Brinecontaining 0.4 lb of salt per gallon ows from an outside source into the tank at a rateof 5 gal/min. The mixture is discharged out of the tank at the same rate of 5 gal/min..Assume that solutions are well-stirred at all times.

Required:
Find the amount of salt in the tank at the end of 40 minutes.

Answers

Answer 1

Answer:

35.94 lb

Step-by-step explanation:

The net mass flow rate dm/dt = flow rate in - flow rate out

mass flow rate in = concentration in × volume flow rate in = 0.4 lb/gallon of salt × 5 gal/min = 2 lb/min

Let m(t) be the mass present at time, t.

So, the concentration at time, t = m(t)/volume of tank = m(t)/100

mass flow rate out = concentration out × volume flow rate out = m(t)/100 lb/gal× 5 gal/min = m(t)/20 lb/min

So, dm/dt = 2 lb/min - m(t)/20 lb/min

So, dm/dt = 2 - m(t)/20

dm/dt = [40 - m(t)]/20

separating the variables, we have

dm/[40 - m(t)] = dt/20

integrating, we have

∫dm/[40 - m(t)] = ∫dt/20

-1/-1 ×∫dm/[40 - m(t)] = ∫dt/20

1/-1 ×∫-dm/[40 - m(t)] = ∫dt/20

1/-1 ×㏑[40 - m(t)] = t/20 + C

-㏑[40 - m(t)] = t/20 + C

㏑[40 - m(t)] = -t/20 - C

taking exponents of both sides, we have

[tex]40 - m(t) = e^({\frac{-t}{20} - C}) \\40 - m(t) = e^{\frac{-t}{20}}e^{-C} \\40 - m(t) = Ae^{\frac{-t}{20}} (A = e^{-C})\\m(t) = 40 - Ae^{\frac{-t}{20}}[/tex]

when t = 0 m(0) = 10 lb

So

[tex]m(t) = 40 - Ae^{\frac{-t}{20}}\\m(0) = 40 - Ae^{\frac{-0}{20}}\\10 = 40 - Ae^{0}\\10 = 40 - A\\A = 40 - 10 \\A = 30[/tex]

So,

[tex]m(t) = 40 - 30e^{\frac{-t}{20}}[/tex]

when t = 40 minutes, m(40) =

[tex]m(40) = 40 - 30e^{\frac{-40}{20}}\\m(40) = 40 - 30e^{-2}\\m(40) = 40 - 30 X 0.1353\\m(40) = 40 - 4.06\\m(40) = 35.94[/tex]

So, at the end of 40 minutes, the amount of salt in the tank is 35.94 lb


Related Questions

what is the factored from of the polynomial function f(x)=x3-6x2+11x-6

Answers

Answer:

[tex]f(x) =(x-1)(x-2)(x-3)[/tex]

Step-by-step explanation:

Given

[tex]f(x) = x^3-6x^2+11x-6[/tex]

Required

The factored form

[tex]f(x) = x^3-6x^2+11x-6[/tex]

Split

[tex]f(x) =x^3 -3x^2- 3x^2 +2x +9x -6[/tex]

Rearrange as:

[tex]f(x) = x^3 -3x^2 +2x - 3x^2+9x -6[/tex]

Factorize

[tex]f(x) = x(x^2 - 3x + 2) - 3(x^2 - 3x + 2)[/tex]

Factor out [tex]x^2 - 3x + 2[/tex]

[tex]f(x) = (x^2 - 3x + 2)(x - 3)[/tex]

Expand

[tex]f(x) = (x^2 - 2x - x + 2)(x - 3)[/tex]

Factorize

[tex]f(x) = (x(x - 2) - 1(x - 2))(x - 3)[/tex]

Factor out [tex]x - 2[/tex]

[tex]f(x) = (x - 1) (x - 2)(x - 3)[/tex]

(PLZ HELP DUE IN 10 MIN)
Eber can mow 4 lawns in one hour. The equation l = 4h can be used to determine the number of lawns, 1. Eber can
mow in h hours. Create a graph to represent the number of lawns Eber can mow in 0 to 5 hours. Click on the
coordinate plane to place the points in the correct locations.

Answers

Answer:

See attachment for plot

Step-by-step explanation:

Given

[tex]l = 4h[/tex]

Required

Represent the scenario on a graph

When h = 0

[tex]l = 4h= 4 * 0 = 0[/tex]

When h = 1

[tex]l = 4 * 1 = 4[/tex]

When h = 2

[tex]l = 4 * 2 = 8[/tex]

When h = 3

[tex]l = 4 * 3 = 12[/tex]

When h = 4

[tex]l = 4 * 4 = 16[/tex]

When h = 5

[tex]l = 4 * 5 = 20[/tex]

So, we have:

[tex](h,l) = (0,0)[/tex]

[tex](h,l) = (1,4)[/tex]

[tex](h,l) = (2,8)[/tex]

[tex](h,l) = (3,12)[/tex]

[tex](h,l)= (4,16)[/tex]

[tex](h,l)= (5,20)[/tex]

See attachment for plot

.a) Imagine you and your friend get a new card with an 18% APR and a $10 minimum payment and use this card to purchase the same mobile phone. If the first friend pays the minimum each month, while the second friend pays $20, what will their balances be after one month?

Answers

Answer:

yes

Step-by-step explanation:

yes yes you need to do the thing yeah

Answer:

yes

Step-by-step explanation:

a) Imagine you and your friend get a new card with an 18% APR and a $10 minimum payment and use this card to purchase the same mobile phone. If the first friend pays the minimum each month, while the second friend pays $20, what will their balances be after one month?

A section of a deck is shaped like a trapezoid. For this section, the length of one base is 41 feet, and the length of the other base is 36 feet. The height is 20 feet. What is the area of this section of the deck?

Answers

Answer:

Step-by-step explanation:

Someone please help me thank you

Answers

P = 20.6, I hope this helps you!!!!!

Using the sine rule, a/sin(A) = b/sin(B) = c/sin(C)

But we have to have at least two angles and two lengths to equate it to one another. We could find the third angle in this triangle to use as our second angle, but we do not know the value of x, so we have to find the second length.

To do that, we use Pythagoras theorem;

a^2 = b^2 + c^2

a^2 = 7^2 + 5^2

a^2 = 49 + 25

a^2 = 74

square root both sides to get rid of the square on a:

a = sqrt(74)

a ~ 8.60

Now we can apply our sine rule. Note that the lengths and angles are the ones opposite each other. For example, the corresponding angle of 8.60 is 90° and the one for 5 is x°.

So,

8.60/sin(90) = 5/sin(x)

8.60/1 = 5/sin(x), since sin(90) = 1

Make sin(x) the subject,

sin(x) = 5/8.60

sin(x) = 0.5814

x = sin^-1(0.5814)

x ~ 35.6°

HELPP IF WRONG ILL REPROT
A store employee conducted a survey of 590 randomly selected customers. According to the survey, 177 of the customers often use coupons.

How many people would you expect to use a coupon if all 5,000 people in the community visited the store?

Question 7 options:

5,310 people


1,250 people


3,750 people


1,500 people

Answers

Answer:

Solution given

:total n[U]=590

customers using coupon n[C]=177

the percentage of all customers who often use coupons=177/590×100%=30%.

If n[U]=5000

no of customer using coupon be x

we have

30% of 5000=x

x=30/100×5000

x=1500

So1500 people would you expect to use a coupon if all 5,000 people in the community visited the store.

Consider the following question: How many years has each person played on the soccer team? Which best describes the question? It is a statistical question because the data may vary for each player. It is a statistical question because the data will all be the same. It is not a statistical question because the answers are all whole numbers. It is not a statistical question because there is only one answer per person.​

Answers

Answer:

Its the first one

Step-by-step explanation:

It is a statistical question because the data may vary for each player. :)

A new car is purchased for $18,000 and over time its value depreciates by one half
every 4 years. What is the value of the car 17 years after it was purchased, to the
nearest hundred dollars?

Answers

Answer:

900

Step-by-step explanation:

THIS IS THE CORRECT ANSWER

what is 15.9% of 261​

Answers

Answer:

41.499

Step-by-step explanation:

Answer:

41.499

Step-by-step explanation:

261x15.9%=261x159/100=41.499

Please help me solve this problem

Answers

Answer:

90°

Step-by-step explanation:

It's simple, the angle of a line is 180°

∠EFG=90°

Line GD-∠EFG=180°-90°=90°

Please mark brainliest!

Help please
(Worth 10 points)
Please respond with a actual answer
*No robots no bad links*

Answers

The dude typing gonna help u

I need help with all 4 questions plz

Answers

2x is the highest common factor of the expression

Plz help me well mark brainliest if correct.....??

Answers

Answer:

C

Step-by-step explanation:

I think it’s C because under the numbers it says pets they own so the x has to be the fourth graders

Answer:

C

Step-by-step explanation:

It says it below the number line!! hoped this helped

A shopkeeper earns a profit of rupees 300 on Monday, a loss of rupees 150 on Tuesday, than a loss of rupees 200 on Wednesday and profit of rupees 50 and rupees 75 on thursday and friday respectively.Find his net profit or loss in 5 days.​

Answers

Answer:

75 rupees in net profit

Step-by-step explanation:

Loss indicates subtraction, and profit indicates addition

300-150-200+50+75=75

Find the perimeter of a quadrilateral with vertices at C (-2, 1), D. (2, 4), E (5,0), and. F (1, -3)
12 units
O 16 units
O 20 units
O 24 units

Answers

It is 20 units and I think you should go with it

What is the answer for 1/2 + 1/2?

Answers

Answer:

1 is the answer to 1/2+1/2

Answer:

1

Step-by-step explanation:

if you add 1/2 and 1/2, you get 2/2 which is also equal to 1.

The following two-way table describes student's
after school activities. Find the probability that a
randomly selected student works, given that it's a
senior.
Grade
Sports
Music/Drama
Work
Sophomore
20
7
3
Junior
20
13
2
Senior
25
5
5
P( Work | Senior) = [?]
Round to the nearest hundredth.

Answers

Answer:

[tex]P(Work | Senior) = 0.14[/tex]

Step-by-step explanation:

Given

The attached table

Required

[tex]P(Work | Senior)[/tex]

This is calculated using:

[tex]P(Work | Senior) = \frac{P(Work \ n\ Senior)}{P(Senior)}[/tex]

This gives:

[tex]P(Work | Senior) = \frac{n(Work \ n\ Senior)}{n(Senior)}[/tex]

From the table:

[tex]n(Work \ n\ Senior) = 5[/tex]

[tex]n(Senior) = 25 + 5+ 5 = 35[/tex]

So:

[tex]P(Work | Senior) = \frac{5}{35}[/tex]

[tex]P(Work | Senior) = 0.14[/tex]

Answer:

14%

Step-by-step explanation:

add 25+5+5 (because that is all the numbers in the 'Seniors' row) and then take the 5 that is in the 'Work' column and put that over 25. (5/25 fraction as a percent is 14).

How can you get a good credit score?
Pay credit card and loan payments late.
Don't apply for credit.
Pay your loan payments on time, every time.
Go above your credit limit.

Answers

Answer:

Pay your loan payments on time, every time.

Step-by-step explanation:

The other answers either hurt or have no effect on your credit score.

The option 2 and 3 is right get a good credit score. Avoid the options 1 and 4.

To get a good credit score, you should follow these steps:

Pay your loan payments on time, every time: Timely payments are one of the most crucial factors in building a good credit score. Consistently paying your bills and loans on or before the due date shows lenders that you are a responsible borrower.

Don't apply for credit excessively: Each time you apply for new credit, a hard inquiry is made on your credit report, which can temporarily lower your score. Applying for multiple credit accounts in a short period may signal financial instability to lenders.

Avoid options 1 and 4:

Paying credit card and loan payments late: Late payments negatively impact your credit score and show a lack of responsibility in managing credit.

Going above your credit limit: Maxing out your credit cards or going above the credit limit can harm your credit score as it indicates a higher risk of defaulting on your debts.

Hence, the option 2 and 3 is right get a good credit score. Avoid the options 1 and 4.

Learn more about Loan here:

https://brainly.com/question/11794123

#SPJ6

Need help on this please

Answers

9514 1404 393

Answer:

  71°

Step-by-step explanation:

Opposite angles of an inscribed quadrilateral are supplementary.

  ∠H = 180° -109° = 71°

_____

Additional comment

The above rule comes from the more general rule that the measure of an inscribed angle is half the measure of the arc it intercepts. Here, inscribed angle J intercepts arc GHI, so that arc has measure 2×109°. Then the measure of short arc GI is 360° -2×109°, and inscribed angle H is half that:

  ∠H = (1/2)(360° -2×109°)

  ∠H = 180° -109° = 71°

Find the focus.
x2 = 6y
A. (0, 3/2)
B. (0,6)
C. (0, -3/2)
D. (3/2,0)

Answers

Answer:

The answer would be (0,3/2) or letter A.

Step-by-step explanation:

In conclusion the answer is letter A (0,3/2)

You welcome.

The co-ordinate of the focus of the given equation of the parabola x^2=6y is (0,3/2).

We have given the equation is

[tex]x^2 = 6y[/tex]

We know that the general equation of the parabola is,

[tex]x^2=4ay[/tex]

A line that passes through the focus and divides the parabola into two halves is known as the axis of symmetry.

What are the coordinates of the focus?

The coordinates of the focus [tex]f(0, a)[/tex]

We have to determine the value of

[tex]a4a=6a \implies 6/4a=3/2[/tex]

Therefore the coordinate of the focus is[tex](0,3/2)[/tex].

To learn more about the focus visit:

https://brainly.com/question/4148030

#SPJ2

The distance traveled by a certain truck varies directly to the amount of fuel the truck consumes. The truck traveled 130 miles on 10 gallons of fuel. At the same rate, how far would the truck travel on 6 gallons of fuel?

Answers

Answer: 78 Miles

Step-by-step explanation:

Daniel measures the growth of his tomato plant and records the results in the table.
What was the average rate of growth during this time period for his plant to thenearest tenth?

Answers

Answer:

1.2

Step-by-step explanation: it just is

Reflect P (-5,10) over the x-axis. What are the coordinates of the reflected point? What quadrant is the reflected point in?

Answers

Answer:

I need the answer 2 QwQ....

Find the area of the figure.
7 cm
4 cm
4 cm
10 cm
10 cm
8 cm
19 cm
area cm2

Answers

Answer:

3404800

Step-by-step explanation:

7 x 4 x 4 x 10 x 10 x 8 x 19 x 2 = 3404800

Hope this helps!!!

Ignacio shares 2.1 liters of water equally into 7 containers. How many milliliters are in each container?

Answers

Answer: 300 ml

Step-by-step explanation:

First and foremost, we should note that:

1000 milliliters = 1 liter

Therefore, 2.1 liters = 2.1 × 1000 = 2100 millimeters.

Therefore, since the liters of water is divided into 7 containers, the vlaue in each container will be:

= 2100 millimeters / 7

= 300 millimeters

4.Kini ang gipasa-pasa nga kinaiya sa pamaagi sa pamuyo sa mga tawo sa
usa ka lugar.
A.Kultura B.Materyal C. Di-Materyal
D.Kinaiya
aano mag two dinhi​

Answers

Answer:

A

Step-by-step explanation:

The answer is A it is Aaaaaa aaaa

Which set of three angles could represent the interior angles of a triangle?
O 19°, 70°, 91°
O 47°, 12°, 31°
O 50°, 20°, 20°
O 25°, 25°, 100°​

Answers

Answer:

19 degrees, 70 degrees, and 91 degrees.

Step-by-step explanation:

The interior angles of a triangle sum to 180 degrees. 19 plus 91 is equal to 110, add 70 to 110 and you'll get 180. :)

19 70 and 91 because that is the answer

Mark is going to purchase a $9,000 motorcycleHis bank will finance his purchase through an add-on interest loan. They will charge Mark 7% interest over 5 years
How much in interest ?

Answers

Answer:

The interest to be charged is $ 3,150.

Step-by-step explanation:

Since Mark is going to purchase a $ 9,000 motorcycle, and his bank will finance his purchase through an add-on interest loan, and they will charge Mark 7% interest over 5 years, to determine how much in interest will be charged, the following calculation has to be done:

9000 x 0.07 x 5 = X

630 x 5 = X

3150 = X

Therefore, the interest to be charged is $ 3,150.

PLEASE HELP MATH QUESTION 10 POINTS HELP ASAP PLEASE HELP
QUESTION IS IN LINKED IMAGE

Answers

Answer:

2x-3y=7. Linear

Blue graph. Linear

Table 3. nonlinear

y=-4. Linear

y=2x^2-4. Nonlinear

y=3/x-2. Nonlinear

Tammy has scored 82, 78, and 93 on her previous three tests. What score does she need on her next test so that her average (mean) is 81?

Answers

Answer:

She needs a grade of 71 on her next text.

Step-by-step explanation:

Mean of a data-set:

The mean of a data-set is the sum of all values in the data-set divided by the number of values.

Tammy has scored 82, 78, and 93 on her previous three tests.

Thus, her grades are 82, 78, 93 and x, in which x is her grade in the fourth test.

There are 4 tests.

What score does she need on her next test so that her average (mean) is 81?

We have to find x when the mean is 81. So

[tex]\frac{82 + 78 + 93 + x}{4} = 81[/tex]

[tex]253 + x = 324[/tex]

[tex]x = 324 - 253[/tex]

[tex]x = 71[/tex]

She needs a grade of 71 on her next text.

Other Questions
2.1 x 10-3 x 2 x 102 =HELPPP PLZ DO NOT PUT ANY LINKS AS YOUR ANSWERTo examine the rhythm in "Annabel Lee," a reader should noteA. the overall meaning of the poem.B. the relationship between the parts.C. the high and low stresses in sound.D. the reappearance of words or ideas. REWARDING BRAINLY TO CORRECT ANSWER Joe said that if you roll a number cube 6 times, one of those rolls will be a 1. Was Joe correct? Why or why not. HRLPFCHfUvFuShdhhshdhdu The general term of a sequence is given by an = 7+3 (n-1) for n > 1.Which recursive formula defines this sequence? A child easily pushes an empty shopping cart around the store. As the cart fills, the child has to exert more force to keep the shopping moving and keep up with his mom. Which law is best supported by this example?A. Newton's First LawB. Newton's Second LawC. Newton's Third LawD. The law of definite proportions Which two of the following are the best ways to improve your credit score?Apply for new credit without actually using itKeep your balances lowPay your bills on timeMove credit card debt aroundNever pay less than the minimum amount Who creates supply in a capitalist society?O the sellerO the buyerO the president O government How did your achievements allow you to show personal development? What skills have you acquired or developed through your work? What steps were taken to ensure the success of your activity? Who did you work with in your activity, and how did you feel about being involved? What obstacles did you encounter, and how did you overcome them? How did your activity help address global issues,either locally,nationally or internationally? How did your participation in your activity affect you and others? What changes would you make if you were to do these activities again? How did your understanding of community change as a result of your S&A activities? Give an example of how you showed initiative and/or a willingness to help others. How did you use your strengths to enhance one of the communities to which you belong? Give an example of how you came up with a solution to resolve an issue in a community to which you belong. Give an example of a situation where you showed commitment to a cause. Do you believe S&A is a valuable experience? Justify your answer.i made mask 6. How many solutions does the system of equations have? (1 point)y - 6x = -3 and y - 6x = -6OonOtwoOnoneO infinitely many During the postclassical era China was the first toA. create poetry and literatureB. Practice the Buddhist religionC. Capture every Japanese IslandD. Use paper money for trade If 2/3 is multiplied by a fraction greater than 1, which of these could be the product? Norra is making a picture frame. She wants the length to be 5 inches more than twice the width. The expression below represents the inches of wood Nora needs to make a picture frame with a width of w inches. just read the picture iwieoeoeoeje The table below shows the average summer temperature increases for regions in Canada. Which of the following conclusions is supported by the data? Please answer this math question for me Read the following excerpt from an article:There is an abundance of new research on hominid fossils.A recent paper published in Science Reports describes nofewer than seventeen studies recently published on thesefossils. The studies are mostly centered in the Middle East,but also take place in parts of China.Which statement best describes the article's level of subjectivity orobjectivity?A. The article is attempting to be objective, but it is really subjective.B. The article is attempting to be subjective, but it is really objective.C. The article is intentionally subjective.D. The article is attempting to be objective and mostly succeeding. What is the function of the introduction introduction paragraph in a expiratory essay Good Evening May You please help me with this question. Samantha decided to calculate the mean absolute deviation of the speed of the cars driving by on a busy highway. She watched the sign showing speed as the cars drove by. The next six cars registered these speeds: {65,72,76,68,79}. Help Samantha calculate.a.4.8 b. 5.3 c. 4.6 d. 4.4