A tank initially has 300 gallons of a solution that contains 50 lb. of dissolved salt. A brine solution with a concentration of 2lb of salt/gallon is admitted into the tank at a rate of 6 gallons per minute. The well-stirred solution is drained at the same rate. How long will it take for the tank to have 100 lb. of dissolved salt

Answers

Answer 1

Let s(t) be the amount of salt in the tank at time t. Then s(0) = 50 lb.

Salt flows into the tank at a rate of

(2 gal/min) (6 lb/gal) = 12 lb/min

and flows out at a rate of

(2 gal/min) (s(t)/300 lb/gal) = s(t)/150 lb/min

so that the net rate at which salt is exchanged through the tank is

ds(t)/dt = 12 - s(t)/150 … (lb/min)

Solve for s(t). The DE is separable, so we have

ds/dt = 12 - s/150

150 ds/dt = 1800 - s

150/(1800 - s) ds = dt

Integrate both sides to get

-150 ln|1800 - s| = t + C

Solve for s :

ln|1800 - s| = -t/150 + C

1800 - s = exp(-t/150 + C )

1800 - s = C exp(-t/150)

s = 1800 - C exp(-t/150)

Now given that s(0) = 50, we solve for C :

50 = 1800 - C exp(-0/150)

50 = 1800 - C

C = 1750

Then the amount of salt in the tank at any time t ≥ 0 is

s(t) = 1800 - 1750 exp(-t/150)

To find the time it takes for the tank to hold 100 lb of salt, solve for t in

100 = 1800 - 1750 exp(-t/150)

1700 = 1750 exp(-t/150)

34/35 = exp(-t/150)

ln(34/35) = -t/150

t = -150 ln(34/35) ≈ 4.348

So it would take approximately 4.348 minutes.

By the way, we didn't have to solve for s(t), we could have instead stopped with

-150 ln|1800 - s| = t + C

Solve for C - this C is not the same as the one we found using the other method. s(0) = 50, so

-150 ln|1800 - 50| = 0 + C

C = -150 ln|1750|

==>   t = 150 ln(1750) - 150 ln|1800 - s|

Then s(t) = 100 lb when

t = 150 ln(1750) - 150 ln(1700)

t = 150 ln(1750/1700)

t = 150 ln(35/34)

t ≈ 4.348


Related Questions

Monica took a survey of her classmates' hair and eye color. The results are in the table below.

Answers

0.14 would be correct

Explain the
The fifth term of a non-linear sequence is 324. The term-to-term rule is ‘multiply by 3?
Work out the second term of the sequence.
Explain the method you used to solve this problem.

Answers

Answer:

a2=12 (the second term of the sequence is 12)

Step-by-step explanation:

a5=324

If the term to term rule is multiply by any number, we deal with geometrical sequence

The formula you should use is an= a1*r^(n-1)  where n is the number of the term which we know. In our case we know

a5, so use 5 instead of n

Then you have a5=a1*r^4 where r is the number 3 (because each next term is greater than previous in 3 times)

a5=324

324= a1*3^4

324=a1*81

a1=4 (We find the first term of sequence, because having it you can easily search for every term )

Return to the formula an= a1*r^n-1

Now search for the second term using 2 instead of n in the formula

a2= a1*r^1

a2=a1*r, a1=4, r=3

a2=4*3=12

Plz solve it
Factorize: no w​

Answers

Answer:

here we can go for two solution

A consumer report counted 72 low-quality, 112 medium-quality, and 711 high-quality computers based on a random sample. The report went on to say that all computers, regardless of quality, are packaged identically and sold at the same price.


Use the observed frequencies to create a probability model for the quality of the next computer purchased.


Input your answers as fractions or as decimals rounded to the nearest hundredth.


Quality Estimated Probability (in %)
___________________________________
-Low- :
-Med- :
-High- :

Answers

Answer:

Low = 72/895

Medium = 112/895

High = 711/895

Step-by-step explanation:

Low = number of low quality products over the total number of products

72 / 72 + 112 + 711

Medium = number of medium quality products over the total number of products

112 / 72 + 112 + 711

High = number of high quality products over the total number of products

711 / 72 + 112 + 711

If my answer is incorrect, pls correct me!

If you like my answer and explanation, mark me as brainliest!

-Chetan K

Answer:

Low

72/895

Medium

112/895

High

711/895

Step-by-step explanation:

please help! i can’t write the equation on here so look at the picture.

Answers

Answer:

So if x= 1 , y= -20 , z = -5 , we just have to replace those values on the equation

[tex]\frac{\sqrt{yz}}{(z-x)^{2} + y } =[/tex]  [tex]\frac{\sqrt{(-20) * (-5)}}{(-5-1)^{2} + (-20) } =[/tex]  [tex]\frac{\sqrt{100}}{(-6)^{2} -20 }[/tex]  [tex]= \frac{10}{16} =\frac{5}{8}[/tex]

Answer:

√100 / {-5-1}^² +(-20)10/(-6)^² -2010/36-2010/165/8

Two lines, C and D. are represented by the equations given below.
Line C: y = x + 10
Line D: y = 3x + 2
Which of the following shows the solution to the system of equations and explains why?
(5, 17), because one of the lines passes through this point
(5. 17), because the point lies between the two axes
(4, 14), because the point does not lie
on any axis
(4, 14), because both lines pass through this point

Answers

The answer is D. (4,14) because both lines pass through this point

Explanation: You can insert (4,14) in either equation and so if you insert it into y= x+10 you get 14=4+10 which shows the x combined with 10 equals the y so it’s correct and if you plotted both lines on the graph both lines would travel through this point because it is a solution for both lines.

find the length of UC

Answers

Answer:

18

Step-by-step explanation:

One way to solve this would be to just solve for random lengths, left to right, until we come to find UC.

We know JK = JH + HM + MK = 82 and JH = 22, so

82 = 22 + HM + MK

subtract 22 from both sides to isolate the unknowns

60 = HM + MK = HK

96 = HK + KU - HU

We know HK = 60

96 = 60 + KU

subtract 60 from both sides to isolate the unknown

We know KU = 36

105 = KN = KU + UC + CN

We know KU = 36 and CN = 51

105 = 36 + 51 + UC

105 = 87 + UC

subtract 87 from both sides to isolate the unknown

18 = UC

UC is what we're looking for, so the problem is solved

Sin³xcosx+sinxcos³x=sinxcosx

Answers

Answer:

Step-by-step explanation:

[tex]sin^3xcosx+sinxcos^3x\\=sinx cosx(sin^2x+cos^2x)\\=sinx ~cosx(1)\\=sin~x~cos~x[/tex]

Find the slope of the line that passes through the points (-12,10) and (-18,14).

Answers

Answer:

-2/3

Step-by-step explanation:

To find the slope we use the formula

m= ( y2-y1)/(x2-x1)

   = ( 14-10)/(-18- -12)

   = (14-10)/(-18+12)

  = 4/-6

 = -2/3

39.) Fiona bought a brand new Harley Davidson motorcycle. Since the weather was nice, she decided to go out for a ride with some of her friends. Before leaving town, she stopped to fill up her motorcycle with gas so that she had a full tank. If Fiona's motorcycle has a 4 gallon gas tank, and she only had to add 2 4/7 gallons, how much gas was in the tank before she filled up?​

Answers

Answer:

1 3/7 gallons

Step-by-step explanation:

Let the amount of gas in the tank before filling was x.

We have:

x + 2 4/7 = 4x = 4 - 2 4/7x = 2 - 4/7x = 1 3/7 gallons

let the amount of gas be x

[tex]\\ \sf\longmapsto x+2\dfrac{4}{7}=4[/tex]

[tex]\\ \sf\longmapsto x+\dfrac{18}{7}=4[/tex]

[tex]\\ \sf\longmapsto x=4-\dfrac{18}{7}[/tex]

[tex]\\ \sf\longmapsto x=\dfrac{28-18}{7}[/tex]

[tex]\\ \sf\longmapsto x=\dfrac{10}{7}[/tex]

[tex]\\ \sf\longmapsto x=1\dfrac{3}{7}[/tex]

evaluate the function f ( -2) = − 3 ^2

Answers

Answer:

f ( -2) = − 3 ^245fsaf

Step-by-step explanation:

f ( -2) = − 3 ^2wqs

f(-2)= -3^2

f(-2) = -3 × (-3)

f(-2) = 9

Must click thanks and mark brainliest

Draw the image of \triangle ABC△ABCtriangle, A, B, C under a dilation whose center is AAA and scale factor is \dfrac{1}{4} 4 1 ​ start fraction, 1, divided by, 4, end fraction.

Answers

The coordinates of the resulting image will be at (1, 1), (3, 4) and (1, 2)

Dilation

Assuming the coordinate of the triangle ABC is A(4, 4), (12, 16) and (-4, -8).

If the coordinate is dilated by a factor of 1/4, the resulting coordinates will be at:

A' = (4/4, 4/4) = (1, 1)

B' = (12/4, 16/4) = (3, 4)

C' = (-4/4, -8/-4) = (1, 2)

Hence the coordinates of the resulting image will be at (1, 1), (3, 4) and (1, 2)

Learn more on dilation here: https://brainly.com/question/10253650

If I have 180$ and a pack of dvds cost 18 how much can I buy

Answers

Answer:

10 packs of dvds

Step-by-step explanation:

$180 / $18 = 10 packs

You can buy a maximum of 10 dvd packs

Answer:

you can buy 10 dvds that is thr answer

Both please please :)…….,,,,,

Answers

Answer:

Step-by-step explanation:

One - 44

88% of 50 is 44

Two - 55296 60,000-4%-4%=55296

Consider the reflection of parallelogram PQRS across the line of reflection wy

Answers

Answer:

Consider the reflection of the parallelogram PQRS across the line of reflection wy if RR = 14 Then RZ= If SX=5 then = 5

Step-by-step explanation:

What is the range of the given data set? OA) 30 OB) 32 OC) 37 OD) 40​

Answers

Answer:

Range = maximum number - minimum number

maximum number = 99minimum number = 62

Range = 99 - 62 = 37

Answer:

37

Step-by-step explanation:

The range is the difference between the highest number and the smallest number.

Looking at the stem and leaf plot we can identify the largest and smallest number

Largest number: 99

Smallest number: 62

If range = largest number - smallest number then range = 99 - 62 = 37

In TUV, u = 17 cm, ZT=11° and ZU=103º. Find the length of t, to the nearest
centimeter

Answers

17 because that is the right answer

2/3 of a number is 20 less than the original number.find the number

Answers

40 40 50 hersssdxddasd

4w - 8 = 32 the value of 4w is 40 how do you know this is true
Please help I will give you Brainlyest

Answers

Answer:

4w = 40

Step-by-step explanation:

Using the addition property of equality to add 8 on both sides gives us the answer to what 4w equals.

[tex]4w - 8 + 8 = 32 + 8\\4w=40[/tex]

Please solve this for 20 points and brainiest

Answers

Answer:

3y² + y - 10

Step-by-step explanation:

Assuming we're finding the area:

[tex](3y-5)(y+2)\\3y^2+6y-5y-10\\3y^2+y-10[/tex]

Answer:

3y² + y - 10

Step-by-step explanation:

(3y -5) (y + 2)

3y² + 6y - 5y  - 10

3y² + y - 10

If m ZABD = 78°, what are mZABC and mZDBC?
(5x+3)
(5x-5)

Answers

ABD = ABC + DBC
Eqivalent to:
78 = (5x + 3) + (5x - 5)
78 = 5x + 5x + 3 - 5
78 = 10x - 2
80 = 10x (move -2 to the left side and get 78 + 2 = 80)
8 = x (80/10 = 8)
With x = 8,
ABC = 5x - 5 = 8*5 - 5 = 40 - 5 = 35
DBC = 5x +3 = 8*5 + 3 = 40 + 3 = 43

Hi, I'm happy to help!

First, we need to solve for x. We know that ABD is 78 degrees. (5x+3), and (5x-5) combined are also 78 degrees. So, we combine the like terms of these to get a new expression.

(5x+3) +(5x-5)

10x-2=78

From here, we want to single out the x, by editing both sides in the same way.

10x-2=78

    +2  +2

10x=80

÷10 ÷10

x=8

Now that we know what x is, we can plug it in to the previous expressions to get the angles of ABC and DBC.

(5x-5)

((5·8)-5)

(40-5)

35

Now, we know that ABC is 35 degrees.

(5x+3)

((5·8)+3)

(40+3)

43

Now, we also know that DBC is 43 degrees.

To verify our answer we can add ABC and DBC together to check if it totals to ABD.

35+43=78

Now, we know that the answer: ABC is 35 degrees and DBC is 43 degrees is correct.

I hope this was helpful, keep learning! :D

There is a loss of Rs 5 when a watch is sold at the discount of 10%. IF the watch is sold at the discount of 5%, there is profit of Rs 22.50. Find the marked price of the watch.​

Answers

at disc of 10% there was 5rupees loss and at disc of 5 % dis there was 22.5 profit
so 5% *x= 22.5+5=27.5
x=27.5 *20
x=550

The area of a square=121m² what is the value of S?​

Answers

Answer:

11 m

Step-by-step explanation:

The area of a square is given by

A = s^2 where s is the side length

121 = s^2

Take the square root of each side

sqrt(121) = sqrt(s^2)

11 = s

Please help its due in 30 minutes will mark braniliest

Answers

Answer:

Step-by-step explanation:

It's a ray. A ray has 1 fixed point. The other end of the ray goes on forever, just as this diagram shows.

1-cot^2a+cot^4a=sin^2a(1+cot^6a) prove it.​

Answers

Step-by-step explanation:

We have

1-cot²a + cot⁴a = sin²a(1+cot⁶a)

First, we can take a look at the right side. It expands to sin²a + cot⁶(a)sin²(a) = sin²a + cos⁶a/sin⁴a (this is the expanded right side) as cot(a) = cos(a)/sin(a), so cos⁶a = cos⁶a/sin⁶a. Therefore, it might be helpful to put everything in terms of sine and cosine to solve this.

We know 1 = sin²a+cos²a and cot(a) = cos(a)/sin(a), so we have

1-cot²a + cot⁴a = sin²a+cos²a-cos²a/sin²a + cos⁴a/sin⁴a

Next, we know that in the expanded right side, we have sin²a + something. We can use that to isolate the sin²a. The rest of the expanded right side has a denominator of sin⁴a, so we can make everything else have that denominator.

sin²a+cos²a-cos²a/sin²a + cos⁴a/sin⁴a

= sin²a + (cos²(a)sin⁴(a) - cos²(a)sin²(a) + cos⁴a)/sin⁴a

We can then factor cos²a out of the numerator

sin²a + (cos²(a)sin⁴(a) - cos²(a)sin²(a) + cos⁴a)/sin⁴a

= sin²a + cos²a (sin⁴a-sin²a+cos²a)/sin⁴a

Then, in the expanded right side, we can notice that the fraction has a numerator with only cos in it. We can therefore write sin⁴a in terms of cos (we don't want to write the sin²a term in terms of cos because it can easily add with cos²a to become 1, so we can hold that off for later) , so

sin²a = (1-cos²a)

sin⁴a = (1-cos²a)² = cos⁴a - 2cos²a + 1

sin²a + cos²a (sin⁴a-sin²a+cos²a)/sin⁴a

= sin²a + cos²a (cos⁴a-2cos²a+1-sin²a+cos²a)/sin⁴a

= sin²a + cos²a (cos⁴a-cos²a+1-sin²a)/sin⁴a

factor our the -cos²a-sin²a as -1(cos²a+sin²a) = -1(1) = -1

sin²a + cos²a (cos⁴a-cos²a+1-sin²a)/sin⁴a

=  sin²a + cos²a (cos⁴a-1 + 1)/sin⁴a

= sin²a + cos⁶a/sin⁴a

= sin²a(1+cos⁶a/sin⁶a)

= sin²a(1+cot⁶a)

Which of the following is equivalent to -12 + 3)?
12 + 31
– 12– 3
o 12 – 3
0 12 + 3

Answers

Answer:

[tex]12 - 3[/tex]

Step-by-step explanation:

[tex]( - 12 + 3) \\ = 12 - 3 \\ =- 9[/tex]

Hope it is helpful....

A rectangular rug has the perimeter of 36 feet. The length of the rug is twice the width. What is the length

Answers

Answer:

12 ft

Step-by-step explanation:

l = 2w

P = 2(l+w)

36 = 2(2w+w)

36 = 2(3w)

36 = 6w

Divide each side by 6

36/6 = 6w/6

6 =w

l = 2w

l = 2(6)

l = 12

simplify : 3p+2p+8-3=15​

Answers

Answer:

3p+2p+8-3=15

5p+5=15

5p=15-5

5p=10

p=10/5

p=2

have a great dayy.

Answer:

p = 2

Step-by-step explanation:

One is given the following equation:

3p + 2p + 8 - 3 = 15

Combine like terms. In essence, if two number have the same variable, then one can perform operations between their coefficients. If two number have no variables, then these two terms are also like terms. After combing like terms, simplify the expression.

3p + 2p + 8 - 3 = 15

5p + 8 - 3 = 15

5p + 5 = 15

Inverse operations,

5p + 5 = 15

5p = 10

p = 2

What is 0.04% of 30? Round to the nearest hundredth

Answers

Answer:

0.012

Step-by-step explanation:

Have a good day.

Answer:

.01

Step-by-step explanation:

Change the percent to decimal form

.04% = .0004

.0004 *30

.012

Round to the nearest hundredth

.01

Simplify [2(5 – 4) + 6(7 – 3)] ÷ 2

I'LL MARK BRAINLY PLEASE HELP ME I'M STRUGGLING

Answers

Answer:

13

Step-by-step explanation:

[2×1+6×4]÷2

[2+24]÷2

26÷2

13

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