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

Somebody helpppp meeee ???

Answers

Answer:

Step-by-step explanation:

plane parallel to the vertical axis :a rectangle

plane parallel to the circular base: a circle

plane making an angle with the vertical axis without passing though the base or top surface :an oval

plane making an angle with the vertical axis and passing through the base and top surface  :a pair of curved lines connected by straight lines at each of their endpoints

plane making an angle with the vertical axis and passing through either the base or the top surface, but not both: a cut-off section of an oval whose boundary has two endpoints connected by a straight line

On a coordinate plane, a triangle has points (negative 5, 1), (2, 1), (2, negative 1).
Use the drop downs to answer the following questions about the distance between the points (−5, 1) and (2, −1).

What is the distance of the horizontal leg?

What is the distance of the vertical leg?

Use the Pythagorean theorem. What is the distance between the two points?

Answers

Answer:

The answer is below

Step-by-step explanation:

The points of the triangle are  (- 5, 1), (2, 1), (2, - 1). The distance between two points is given by:

[tex]Distance=\sqrt{(x_2-x_1)^2+(y_2-y_1)^2}[/tex]

The horizontal leg is formed by points with the same y axis. Therefore the points that make up the horizontal leg is (- 5, 1), (2, 1). The Distance of the horizontal leg is:

[tex]Horizontal\ leg=\sqrt{(2-(-5))^2+(1-1)^2}=\sqrt{7^2+0}=7\ units[/tex]

The vertical leg is formed by points with the same x axis. Therefore the points that make up the vertical leg is (2 1), (2, 1-). The Distance of the vertical leg is:

[tex]Vertical\ leg=\sqrt{(2-2)^2+(-1-1)^2}=\sqrt{0+(-2)^2}=2\ units[/tex]

The hypotenuse is gotten using Pythagorean theorem. It is gotten by:

Hypotenuse² = (Horizontal leg)² + (Vertical leg)²

Hypotenuse² = 7² + 2²

Hypotenuse² = 49 + 4 = 53

Hypotenuse = √53

Hypotenuse = 7.28 unit

Answer:

The answer are 7, 2 and 53

Step-by-step explanation:

draw the graph of linear equation 5y = 3x + 18 on a cartesian plane. From the graph check weather (-2,4) is the solution of the linear equation or not PLS URGENT ANSWER

Answers

Answer:

The point (-2, 4) is not a solution of the linear equation, 5·y =  3·x + 18

Please find attached the required graph of the linear equation 5·y =  3·x + 18 written in the form y = 3/5·x + 18/5

Step-by-step explanation:

The given equation is 5·y = 3·x + 18, from which we have;

y = 3/5·x + 18/5

To draw the graph, we generate for vales of y corresponding to values of x as follows;

x,      y

-6,    0

-5,    0.6

-4,    1.2

-3,    1.8

-2,    2.4

-1,      3

0,      3.6

1,       4.2

2,      4.8

3,      5.4

4,       6

5,       6.6

6,       7.2

7,        7.8

8,        8.4

9,        9

10,      9.6

11,       10.2

12,      10.8

13,      11.4

14,       12

15,      12.6

16,      13.2

Therefore, when y = 0, x = -6, when x = 0, y = 3.6, when x = -2, y = 2.4, when y = 4, x = -2, x = 6

Therefore, the point (-2, 4) is not a solution of the linear equation, 5·y =  3·x + 18

What is the image of the point (3, 2) after a rotation of 90° counterclockwise about the origin?​

Answers

(-2,3). When rotating a point 90 degrees counterclockwise about the origin our point A(x,y) becomes A'(-y,x).

can you please tell me the answer I don't know ​

Answers

Answer:

Twenty-eight billion five hundred forty-two million rupees

28,542,000,000 rupess

or, 28.542 × 10⁹ rupees

Solve one-step equations

Answers

Where are the equations?

A pair of parallel lines intersected by a transversal and forms same side interior angles that are in a 5:1 ratio. what are the measures of two same side interior angles?

Answers

Answer:

1st side: 150

2nd side: 30

& A wall is 20 m long and 5 m high. Find the area of the wall. How many 2 m long 2 m broad flex be fitted on the wall? Suppo tanks the se be and Cuboid​

Answers

Area of wall = l×b

Length = 5m

Breadth = 20m

Area = 5×20

=100m²

Area of flex = side×side

= 2×2

= 4m²

Now no of flex that can be fitted = 100/4

= 25 flex

Must click thanks and mark brainliest

please help

The midpoint (x, y) and the end point (x2, y2) are known. Find (x1, Y1) using the midpoint formula.

a. (x1,y1) = (2x + x2, 2y+y2)

b. (x1,y1) = (2x - x2, 2y - y2)

c. (x1,y1) = (x + x2, y + y2)

d. (x1,y1) = (x - x2, y - y2)

Answers

Answer:

B

Step-by-step explanation:

So this was a pretty difficult question to do algebraically so I just came up with an example.

Step-by-step explanation:

Hey,there!!!

Let's simply work with it,

We have,

One point is (x2,y2) and midpoint is(x,y).

Now, let's use midpoint formulae,

[tex](x ,\: y) = \frac{x1 + x2}{2} + \frac{y1 + y2}{2} [/tex]

Now, let's equate with their corresponding elements we get,

[tex]x = \frac{x1 + x2}{2} [/tex]

now, 2x=x1+x2

or, x1=2x-x2

and

[tex]y = \frac{y1 + y2}{2} [/tex]

now,

2y = y1+y2

or, y1 = 2y-y2

Therefore, the answer is (x1,y1)= { (2x-x2),(2y-y2) }

Hope it helps...

What is the 6th term of this pattern : 0.1, 0.02, 0.12, 0.14, 0.26, ____?




If you will solve i will give brainliest.

Answers

Answer:

0.28

Step-by-step explanation:

Raj tested hist new flashlight by shining it on his bedroom wall. The beam of light can be described by his equation x^{2}+y^{2}-2x-4y-31=0. How many inches wide is the beam of light on the wall?

Answers

Answer:

Diameter=12 inches

Step-by-step explanation:

Given:

x^{2}+y^{2}-2x-4y-31=0

Using completing the square

x^2 - 2x + 1 + y^2 - 4y + 4 = 31+1+4

(x-1)^2 + (y-2)^2 = 36

Rewrite in the form

(x-h)^2+(y-k)^2=r^2

We have,

(x-1)^2+(y-2)^2=6^2

radius = 6

Diameter =radius ×2

=6 × 2

diameter = 12 inches

help pleasseeeeeeeee

Answers

Answer:

-1

Step-by-step explanation:

I know that i^4 = 1

i^10 = i^4 * i^4 * i^2

     = 1 * 1 * i^2

We know that i^2 = -1

    =1 *1 *-1

    = -1

This system of linear inequalities can be used to find the possible heights, in inches, of Darius, d, and his brother William, w. d ≥ 36;w < 68;d ≤ 4 + 2w
Which statements must be true about their heights?

Answers

Answer:A,C,F

Step-by-step explanation:edge2020

Answer:

A,C,F

Step-by-step explanation:

Jonathan took 5 minutes to walk to the bus-stop, then spent 63 minutes waiting for the bus. If the bus journey to his school took 10 minutes, how much time did he take to reach his school?​

Answers

Answer:

78 minutes or 1 hour and 18 minutes

Step-by-step explanation:

Add 5 and 63 and 10

In the right triangle ABC, angle A is 36 degrees.

Answers

Answer:

Step-by-step explanation:

The best way to start this question is to find the value of the big 3. The big three (on your calculator) are the sin cos and the tangent. Once you have them, the other three are just the reciprocals.

Sin36 = 0.588

Cos36= 0.809

Tan36 = 0.727

============

Now for the other three, which are not on your calculator (directly)

Csc(36) = 1/sin(36) = 1/0.588 = 1.70

Sec(36) = 1/cos(36) = 1/ 0.809 =  1.236

cot(36) = 1/tan(36) = 1/0.727 = 1.376

I don't know if you remember who marries who here. I always remember that cofunction goes with the non cofunction. So the sin and csc are going out together. The cot and tan are dating etc.

collen family plans to paint the window of their house. her father will paint twice as many window as her mother, and collen and her 2 brothers will paint an equal number of the rest of the windows. How many windows are there

Need Help Will Mark Brainlist

Answers

Answer:

21 windows

Step-by-step explanation:

collen family plans to paint the windows of their house. her father will paint twice as many windows as her mother, and collen and her 2 brothers will paint an equal number of the rest of the windows. Colleen decided to do her own share and her mother's share and paints 7 window, which is one less than her father's share. how many windows are in their house?

Answer: Let the number of window Collen father would paint be a while that of her mother be b. Since her father will paint twice as many window as her mother, therefore the number of windows painted by the father a = 2b

Let the number of windows that would be needed to be painted each by Colleen and her 2 brothers be c because they would paint the equal number of windows.

The total number of windows to be painted = 2b + b + c + c + c = 3b + 3c = 3(b + c).

Collen painted 7 windows as her mother and her own share which is one less than the fathers share. Therefore b + c = 7.

Also the fathers share a = 2b = 7 + 1 = 8 windows. Therefore b = 4 which is the mother share

Therefore the total number of windows = 3(b + c) = 3(7) = 21 windows

3b + 3c =  21

3(4) + 3c = 21

12 + 3c = 21

3c = 21 - 12

3c = 9

c = 3 which is collen and her brothers share

The hanger diagram models the equation 2(n + 7) = 24. What could be the
first step in using the diagram to find the value of n? What could be the first
step reasoning about the equation to find the value of n? How are these
steps the same or different?
Please help

Answers

Step-by-step explanation:

first of all you times every number with two 2(n-7) then collect like terms then divide

Write in standard 7.125×10^-9

Answers

Answer:

7.125*10⁻⁹ = 0.000000007125

Step-by-step explanation:

7.125*10⁻⁹ = 0.000000007125

I will give brainliest to the right answer!! Find the vertex and the length of the latus rectum. x= 1/2 (y - 5)² + 7

Answers

Answer:

(7, 5)2

Step-by-step explanation:

When the quadratic is written in vertex form:

  x = a(y -k)^2 +h

the vertex is (x, y) = (h, k), and the length of the latus rectum is 1/a.

For your given equation, ...

  x = (1/2)(y -5)^2 +7

you have a=1/2, k = 5, h = 7, so ...

  the vertex is (7, 5)

  the length of the latus rectum is 1/(1/2) = 2

!!!!25 POINTS!!!!!

What is:

65.74 x .88


Answers

Answer:

5785.12

Step-by-step explanation:

I showed the picture instead of explaining

n circle L, arc NOP is 90° and the radius is 5 units. Which statement best describes the length of arc NOP? circle M with radii LM, LN, LO, and LP so that arc MNOP is created

Answers

Answer:

[tex]\frac{1}{4} \times 2\pi r[/tex] i.e circle circumference

Step-by-step explanation:

Data provided as per the question is

Arc NOP = Central angle = [tex]\theta = 90^\circ[/tex]

The Radius of circle = 5 units

The statement is shown below:-

we need to determine the statement which defines the best length of arc NOP

Arc length is

= [tex]\frac{control\ angle}{360} \times circumference\ of\ circle[/tex]

now we will put the values into the above formula

= [tex]\frac{90}{360} \times 2\pi r[/tex]

= [tex]\frac{1}{4} \times 2\pi r[/tex]

Hence, the [tex]\frac{1}{4} \times 2\pi r[/tex] i.e circle circumference is the best statement described.

A turtle was crawling at the rate of 43 cm per minute. How many kilometers would this turtle crawl in one day (24 hours) if it did not rest and continued to crawl at a continuous pace?

Answers

Answer:

0.6192

Step-by-step explanation:

f) 60 students in a hostel have food enough for 30 days. If 20 more students join the hostel after 10 days, how long will the remaining food last?

Answers

Answer:

Hello,

10 days

Step-by-step explanation:

60 étudiants dans un foyer ont assez de nourriture pour 30 jours. Si 20 étudiants supplémentaires rejoignent l'auberge après 10 jours, combien de temps durera la nourriture restante ?

Let say A the quantity of food

60 students in a hostel have food enough for 30 days ==> A=k*60*30

==> k=A/1800

Let say x the duration of the food.

60 students for x days + 20 students for (x-10) days =A

[tex]k*60*x+k*20*(x-10)=A\\[/tex]

[tex]\dfrac{A*60*x}{1800} +\dfrac{A*20*(x-10)}{1800} =A\\\\60x+20x-200=1800\\\\80x=1600\\\\x=20\\[/tex]

Duration for the 80 students: 20-10=10days

what is the gcf of 3x^2 +9

Answers

Answer:v

Step-by-step explanation:

3(x^2+3)

the gcf is 3

Answer: 3 is the gcf

Step-by-step explanation:

3 is a factor of both 3 and 9. 1 is the other common factor. 3 is the greatest common factor. If you were looking at larger numbers with many common factors like 24 and 48, factors include 1,2,3,4,6,8,12,&24 You might find other smaller factors useful, but most of the time it's the gif that needs to be factored out: 3(x^2 + 3)

what is acceleration produced by a force of 12 newton exerted on an object of mass 3kg​




please use latex because I have to copy this

Answers

Answer:

[tex] 4 ms^{-2} [/tex]

Step-by-step explanation:

[tex] \because Force = mass \times acceleration \\

\therefore Acceleration = \frac {Force} {mass} \\

= \frac {12}{3} \\

= 4 ms^{-2} [/tex]

Step-by-step explanation:

[tex]as \: we \: know \: that \: force = mass \times accerlation \: [/tex]

[tex]so \: it \: means \: accerltion = \frac{mass}{force} [/tex]

[tex]so \: put \: the \: values [/tex]

[tex]acceleration = \frac{12}{3} [/tex]

[tex]after \: solving \: it \: we \: get \: the \: answer \: 4[/tex]

a = 4 is ur answer

so the acceleration is 4 m/s.^2

Hope it helps u

The circumference of a circle is 97 m.
What is the area of the circle?
O 4.57 m²
o 187 m²
0 20.257 m2
O 817 m2

Answers

Answer

295.4426m²

Step-by-step explanation:

97m÷2=48.5

a=πr²a=(π×48.5)²a= (3.14×94.09)a= 295.4426m²

A circle has a radius of 11m . Find the radian measure of the central angle that intercepts an arc of length 6 m .

Answers

Answer:

Step-by-step explanation:

θ=l/r

θ=6/11 radians

≈0.555... radians

Write 30+x^2-11 in standard form.​

Answers

Answer:

x^2+19

Step-by-step explanation:

A portion of a line or Ray that extends from one point to another point is called what

Answers

Answer: line segment

Step-by-step explanation:

A line segment is a ray that extends from one point to another. Hope this helps!

Answer:

line segment

Step-by-step explanation:

If a portion of a line has two endpoints (two little black dots on its end), then it is a line segment.

If it has one dot and an arrow, its a ray. This has an endpoint and goes on forever in the direction of the arrow.

HELP ASAP
Points $A(-1, -2)$ and $B(3, 2)$ are the endpoints of a diameter of a circle graphed in a coordinate plane. How many square units are in the area of the circle? Express your answer in terms of $\pi$.

Answers

Answer:

8π units²

Step-by-step explanation:

center=((-1+3)/2,(-2+2)/2)=(1,0)

[tex]radius~r=\sqrt{(3-1)^2+(2-0)^2} =\sqrt{4+4} =\sqrt{8} \\area~of~circle=\pi r^2=\pi \times (\sqrt{8} )^2=8\pi ~square~units.[/tex]

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