Answer:28.26
Step-by-step explanation:
Φ=180 since it's in a straight line
Radius=r=9
π=3.14
Length of arc=Φ/360 x 2 x π x r
Length of arc=180/360 x 2 x 3.14 x 9
Length of arc=0.5 x 2 x 3.14 x 9
Length of arc=28.26
Two tanks are interconnected. Tank A contains 60 grams of salt in 50 liters of water, and Tank B contains 80 grams of salt in 40 liters of water.
A solution of 2 gram/L flows into Tank A at a rate of 5 L/min, while a solution of 3 grams/L flows into Tank B at a rate of 7 L/min. The tanks are well mixed.
The tanks are connected, so 8 L/min flows from Tank A to Tank B, while 3 L/min flows from Tank B to Tank A. An additional 12 L/min drains from Tank B.
Letting x represent the grams of salt in Tank A, and y represent the grams of salt in Tank B, set up the system of differential equations for these two tanks.
Let a(t) and b(t) denote the amounts of salt in tanks A and B, respectively.
The volume of liquid in tanks A and B after t minutes are
A: 50 L + (5 L/min + 3 L/min - 8 L/min)t = 50 L
B: 40 L + (7 L/min + 8 L/min - 3 L/min - 12 L/min)t = 40 L
so the amount of solution in the tanks stays constant.
Salt flows into tank A at a rate of
(2 g/L)*(5 L/min) + (b(t)/40 g/L)*(3 L/min) = (10 + 3/40 b(t)) g/min
and out at a rate of
(a(t)/50 g/L)*(8 L/min) = 4/25 a(t) g/min
so the net flow rate is given by the differential equation
[tex]\dfrac{\mathrm da(t)}{\mathrm dt}=10+\dfrac{3b(t)}{40}-\dfrac{4a(t)}{25}[/tex]
We do the same for tank B: salt flows in at a rate of
(3 g/L)*(7 L/min) + (a(t)/50 g/L)*(8 L/min) = (21 + 4/25 a(t)) g/min
and out at a rate of
(b(t)/40 g/L)*(3 L/min + 12 L/min) = 3/8 b(t) g/min
and hence with a net rate of
[tex]\dfrac{\mathrm db(t)}{\mathrm dt}=21+\dfrac{4a(t)}{25}-\dfrac{3b(t)}8[/tex]
Replace a(t) and b(t) with x and y. Then the system is (in matrix form)
[tex]\dfrac{\mathrm d}{\mathrm dt}\begin{bmatrix}x\\y\end{bmatrix}=\dfrac1{200}\begin{bmatrix}-32&15\\32&-75\end{bmatrix}\begin{bmatrix}x\\y\end{bmatrix}+\begin{bmatrix}10\\21\end{bmatrix}[/tex]
with initial conditions x(0) = 60 g and y(0) = 80 g.
What is the sum of 6 x 12?
Answer:
72
Step-by-step explanation:
because 6 x 10 is 60 so 6 x 2 is 12, so 12 + 60 is 72.
Twenty words were randomly selected from two textbooks. Each set gives the number of letters in each of the twenty words for that textbook.
Briefly describe how the word lengths compare between textbook 2 and textbook 1.
Briefly describe the variability in the length of words in textbook 2 compared to textbook 1. PLEASE HURRY :(
Answer:
k = 13The smallest zero or root is x = -10
Step-by-step explanation:
you can write "x^2" to mean "x squared"
f(x) = x^2+3x-10
f(x+5) = (x+5)^2+3(x+5)-10 ... replace every x with x+5
f(x+5) = (x^2+10x+25)+3(x+5)-10
f(x+5) = x^2+10x+25+3x+15-10
f(x+5) = x^2+13x+30
Compare this with x^2+kx+30 and we see that k = 13
Factor and solve the equation below
x^2+13x+30 = 0
(x+10)(x+3) = 0
x+10 = 0 or x+3 = 0
x = -10 or x = -3
The smallest zero is x = -10 as its the left-most value on a number line.
The perimeter of a rectangle is 62 meters. The length is 4 more than 2 times the width. What is the length?
Answer:
4x+ 1 = 24 + 1 = 25 m.
Step-by-step explanation:
Given, perimeter = 62 m. Perimeter : 2 (L+W) = 62 m. hence, L+W = 31 m. x = 30/5
Answer:
Step-by-step explanation:
let width be x
length = 2x + 4
2(x + 2x + 4) = 62
6x + 8 = 62
6x = 54
x = 9
length = 2(9) + 4 = 22cm
Sara Bought a computer that was originally priced at $896.The computer was on sale for 12% off. When she bought the computer, a 7% tax was added to the sale price. How much did Sara spend on the computer. Round to the nearest cent!
Answer:
$733.29. Simply because you take $896•0.12 to find the 12% off and then you take that subtracted by the starting total. After you get the 12% off then you multiply that number by .07 to get the sales tax. After you find that then you add the number you got after multiplying to the number you got after taking off the 12%.
Step-by-step explanation:
Write the perimeter of the floor plan shown as an algebraic expression in x.
Answer: 8+2x
Step-by-step explanation:
Hi, Perimeter is the distance around a two-dimensional shape.
To calculate it, we have to add all the side lengths of the figure. The missing side is the ? side (right side). To obtain it we have to subtract the top right side length (2) to the left side length (12)
So, the expression is equal to:
P = 12+ (x-4) + (x-12) +2 +(12-2)
P = 12+ x - 4 +x -12+2 +10
P = 12-4-12+2+10+x+x
P =8+2x
Erin built a wooden box to hold hay on her farm. The box is 3 m long, 1 m wide, and 1 m high. Hay costs $14 per cubic meter.
Answer:
It will cost 42 to completely fill the box with hay.
have a good day <3
In ΔPQR, the measure of ∠R=90°, RP = 9.9 feet, and QR = 3.2 feet. Find the measure of ∠P to the nearest tenth of a degree.
Answer:
17.9
Step-by-step explanation:
What is 1 2/3 - 2 1/3?
Step-by-step explanation:
First it will be easer if you turn both sides into improper fractions
5/3-7/3
Now do 5-7
5-7=-2
The bottom of the fraction stays the same
-2/3 is your answer.
change 5 out of 19 to a percentage
Answer:
26.3%
Step-by-step explanation:
5 is divided by 19
That answer is then multiplied by 100.
You may round your answer to the nearest whole number.
Parallel lines s and t are cut by a transversal, r.
Parallel lines s and t are cut by transversal r. Clockwise from top left, the angles formed with r and s are 1, 2, 3, 4; the angles formed with r and t are 5, 6, 7, 8.
If the measure of angle 1 is 68°, what is the measure of angle 5?
22°
68°
112°
158°
Answer:
68°
Step-by-step explanation:
Angles 1 and 5 are corresponding angles on parallel lines, hence they are equal
Answer:
B.
Step-by-step explanation:
a circle with area 36pi has a sector with a central angle of 48°. what is the area of the sector?
Answer:4.8π
Step-by-step explanation:
Φ=48°
Area of circle=36π
Area of circle=π x r^2
36π=πr^2
Dividing both sides by π we get
r^2=36π/π
r^2=36
Take them square root of both sides
√(r^2)=√(36)
r=6
Area of sector=Φ/360 x π x r x r
Area of sector=48/360 x π x 6 x 6
Area of sector=(48xπx6x6)/360
Area of sector=1728π/360
Area of sector=4.8π
Simplifying products and quotients of powers
7^2•7^8/7^4=7^a/7^4=7^b
A=
b=
Answer:
a=10
b=6
Step-by-step explanation:
add 2 to 8, to get a, then subtract 4 from 10 to get b
Answer:
10 and 6
Step-by-step explanation:
Which expression can be used to find the area of the rectangle shown on the coordinate plane 6×7 7×7 8×7 8×8
Answer:that’s a lot of numbers.
Step-by-step explanation:
I really need help!! HELP ASAP PLEASE!!!
Which figure has an area of 12 square units?
Answer:
Should be the bottom one
Step-by-step explanation:
You can find this by counting. It is the only one with 12 units.
Answer:
Step-by-step explanation:is number 4 i pick it and its correct
There are 14 math teachers and 26 science teachers at
school today. What is the ratio of math teachers to math
and science teachers at school?
Answer: 2.86
Step-by-step explanation:
14+26=40
40/14
Answer:
2.86
Step-by-step explanation:
a number rounded to the nearest hundred thousand is 400,000 the same number rounded to the nearest ten thousand is 350,000 what could be the number
Answer:350000
Step-by-step explanation:
The number is 350000
350000 rounded to the nearest hundred thousand is 400000
350000 rounded to the nearest ten thousand is 350000
Find the arc length of the partial circle. with a radius of 1
Answer:
1/2π
Step-by-step explanation:
For khan, you HAVE to put the pi symbol. just type pi and itll work
Answer:
1/2 pi (Sorry i don't have the pi symbol)
Step-by-step explanation:
What function has zeros at x=10 and x=2
Answer:
f(x) = x^2 -12x +20
Step-by-step explanation:
There are an infinite number of functions with zeros at those values of x. One simple polynomial function with those zeros is ...
f(x) = (x -10)(x -2) . . . . . each zero contributes a factor
f(x) = x^2 -12x +20
Talia is going to put a new carpet in her house. She measure's one side of her living room and finds it measures 17 meters which measurement does 17 meters represent
The answer in length
The length is used to measure the distance between to end points or edges. so 17 meters measurement represent the length.
What is perimeter?Its the sum of length of the sides used to made the given figure.
Talia is going to put a new carpet in her house. She measure's one side of her living room and finds it measures 17 meters.
Area is what is on the inside.
The perimeter is the outside of the hole thing.
Hence, the length is used to measure the distance between to end points or edges.
so 17 meters measurement represent the length.
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What’s the correct answer?
Answer:
B.
Step-by-step explanation:
Answer:b
Step-by-step explanation:you need to add both
a candlemaker prices one set of scented candles at $10
y=10x
x= how many candles
A medical researcher is studying the spread of a virus in a population of 1000 laboratory mice. During any week, there is an 80% probability that an infected mouse will overcome the virus, and during the same week there is a 10% probability that a noninfected mouse will become infected. Three hundred mice are currently infected with the virus. How many will be infected next week and in 3 weeks
Answer:
The number of mice that will be infected next week are 130 while
The number of mice that will be infected in 3 weeks are 111
Step-by-step explanation:
From the information given , the researcher is studying the spread of a virus in a population of 1000 laboratory mice. i.e, n = 1000
Number of infected = 300
Non infected = 1000 - 300 = 700
Probability an infected mouse will overcome = 80% = 0.8
Probability a noninfected mouse becomes infected = 10% = 0.10
The number of infected that will overcome = 0.8 * 300 = 240
The number of non infected that will become infected = 0.1 * 700 = 70
The number that will be infected on the first week =
300 - 240 + 70
= 130
Number that will be healthy on the first week =
700 + 240 - 70
= 870
Calculating for week 2:
The number of infected that will overcome = 0.8 * 130 = 104
The number of non infected that will become infected = 0.10 * 870 = 87
The number that will be infected on the second week =
130 - 104 + 87
= 113
Number that will be healthy on the second week =
870 + 107 - 87
= 887
Calculating for week 3:
The number of infected that will overcome = 0.8 * 113 = 90.4
The number of non infected that will become infected = 0.10 * 887 = 88.7
The number that will be infected on the third week =
113 - 90.4 + 88.7
= 111.3 ≈ 111
Number that will be healthy on the third week =
887 + 90.4 - 88.7
= 888.7 ≈ 889
From our calculations, the number of mice that will be infected next week are 130
The number of mice that will be infected in 3 weeks are 111
What is a Regression equation
Answer:
Regression equations can help you figure out if your data can be fit to an equation.This is extremely useful if you want to make predictions from your data- either future predictions or indications of past behavior.For example,you might want to know what your savings are going to be worth in the future.There are several types of regression equations,some of the more common include exponential and simoke linear regression.In elementary statistics,the regression equation you are most likely to come across is the linear form.
Matt says 3/3 is equivalent to 1 is he correct?
Answer: Yes
Step-by-step explanation:
It isn't an
1 an improper fraction
Less than the denominator
Therefore, three thirds or 3/3 is one whole fraction
Rly hope I helped!
☆꧁Ashlin꧂☆
Answer:yes he his correct
Step-by-step explanation:
3/3=1
A North American company manufactures rivets for use in car production. A sample of forty rivets from the production line had mean 6.803 and standard deviation 0.275 (both in 1/100 of an inch). On communicating these results to the company headquarters in Europe, a request is made for the summary statistics to be converted into millimeters. Given that one inch is 2.538 centimeters, find the mean and standard deviation of the sample in millimeters. What is the mean in millimeters
Answer:
Mean = 1.73 mm
Standard deviation = 0.0698 mm
Step-by-step explanation:
Given:
Sample size, n = 40
Mean, u = 6.803
Standard deviation = 0.275
a) Given that one inch is 2.538 centimeters, to find the mean in millimeters we have:
[tex] 6.803 * \frac{1}{100} [/tex]
Converting to cm, we have:
[tex] 6.803 * \frac{1}{100} * 2.538 = 0.173 cm[/tex]
Converting to mm, we know 1cm = 10 mm,
0.173 * 10 = 1.73 mm
b) Given that one inch is 2.538 centimeters, to find the standard deviation in millimeters we have:
[tex] 0.275 * \frac{1}{100} [/tex]
Converting to cm, we have:
[tex] 0.275 * \frac{1}{100} * 2.538 = 0.00698 cm[/tex]
Converting to mm, we know 1cm = 10 mm,
0.00698 * 10 = 0.0698mm
In this exercise we have to use the knowledge of statistics to calculate the car production, so we have to:
Mean: [tex]1.73mm[/tex]Standard deviation: [tex]0.0698 mm[/tex]Given the following information, we have:
Sample size n = 40 Mean u = 6.803 Standard deviation = 0.275A) Find the convertion to the mean in milimeters, will be:
[tex]6.803*(1/100)*2.538=0.173 cm\\=1.73 mm[/tex]
B) Find the convertion to the stardard deviation in milimeters, will be:
[tex]0.275*(1/100)*2.538=0.00698\\=0.0698 mm[/tex]
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what is the equation to the following sentence?
Seven subtracted from two times a number is 13
Answer:
4x-7>13
add 7
4x>20
divide by 4
x>5
Step-by-step explanation:
Some shrubs have the useful ability to resprout from their roots after their tops are destroyed. Fire is a particular threat to shrubs in dry climates, as it can injure the roots as well as destroy the aboveground material. One study of resprouting took place in a dry area of Mexico. The investigation clipped the tops of samples of several species of shrubs. In some cases, they also applied a propane torch to the stumps to simulate a fire. Of 19 specimens of a particular species, 6 resprouted after fire. Estimate with 96% confidence the proportion of all shrubs of this species that will resprout after fire. Interval: .1884 to
The 96% confidence interval for the proportion of all shrubs of this species that will resprout after fire is approximately 0.1274 to 0.5042.
Here, we have,
To estimate the proportion of all shrubs of this species that will resprout after fire with 96% confidence, we will use the formula for a confidence interval for a proportion.
The formula for the confidence interval for a proportion (p) is given by:
CI = p ± Z * √(p * (1 - p) / n)
where:
CI is the confidence interval
p is the sample proportion (resprouted specimens / total specimens)
Z is the critical Z-score corresponding to the desired confidence level (96% confidence level corresponds to a Z-score of approximately 1.750)
n is the sample size (total number of specimens)
Given information:
Total number of specimens (n) = 19
Number of specimens that resprouted after fire = 6
Now, calculate the sample proportion (p):
p = (number of specimens that resprouted) / (total number of specimens)
p = 6 / 19 ≈ 0.3158 (rounded to four decimal places)
Now, calculate the critical Z-score for a 96% confidence level (use a Z-table or calculator):
Z ≈ 1.750
Now, calculate the margin of error (E):
E = Z * √(p * (1 - p) / n)
E = 1.750 * √(0.3158 * (1 - 0.3158) / 19)
E ≈ 0.1884 (rounded to four decimal places)
Finally, calculate the confidence interval:
CI = p ± E
CI = 0.3158 ± 0.1884
The 96% confidence interval for the proportion of all shrubs of this species that will resprout after fire is approximately 0.1274 to 0.5042.
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What type of lines are shown?
Answer:
the angle is acute angle
Answer:
The type of angle shown is an acute angle
Step-by-step explanation:
there are 4 main types of angles. this is an acute angle as it is less than 90°.
Types of angles:
The 4 main types of angles are: acute, obtuse, right angles, reflex angles.
Acute angles- Acute angles are angles less than 90°.
Obtuse Angles-Obtuse angles are angles greater than 90° but less than 180°.
Right Angles- Right angles are angles of 90°.
Reflex Angles- Reflex angles are angles greater than 180° but less than 360°.
Determine the value of x for the triangle. show work.
Answer:
x=5
Step-by-step explanation:
x, x+7, x+8 must be a Pythagorean triple for it to make a right triangle. The only Pythagorean triple fitting these numbers is 5, 12, 13 so x must be 5.
Answer:
5
Step-by-step explanation:
Because this is a right triangle, you know that by the Pythagorean theorem:[tex]\sqrt{(x+7)^2+x^2}=x+8[/tex]
Squaring both sides to get rid of the square root:
[tex](x+7)^2+x^2=(x+8)^2[/tex]
Expanding all of the parentheses:
[tex]x^2+14x+49+x^2=x^2+16x+64[/tex]
Combine like terms:
[tex]x^2-2x-15=0[/tex]
Factor:
[tex](x-5)(x+3)=0[/tex]
Since x cannot be negative, it is equal to 5. Hope this helps!
