Answer:
a. [tex]dA(t)/dt = 50 - \frac{7A(t)}{400} where A(0) = 400[/tex]
b. [tex]A(t) = \frac{20000}{7} + \frac{17200}{7}e^{-7t/400}[/tex]
c. 3.717 kg
Step-by-step explanation:
a) Write the differential equation that represents the problem.
Let A(t) be the amount of dissolved oxygen in the tank at any time, t.
The net flow rate dA(t)/dt = mass flow in - mass flow out
Since 10 g/l of oxygen flows in at a rate of 5 l/min, the mass flow in is 10 g/l × 5 l/min = 50 g/min
Since A(t) is the amount of oxygen present in the tank at time, t, and the volume of the tank is 400 liters. The concentration of oxygen in the tank is thus A(t)/400 g/l.
Also, water is being pumped out at a rate of 7 l/min. So, the mass flow out is thus concentration × flow rate out = A(t)/400 g/l × 7 l/min = 7A(t)/400 g/min
So, dA(t)/dt = mass flow in - mass flow out
dA(t)/dt = 50 - 7A(t)/400 with A(0) = 400 l × 1 g/l = 400 g since the tank initially contains 1 g/l of dissolved oxygen and has a volume of 400 l
So, the differential equation is
dA(t)/dt = 50 - 7A(t)/400 where A(0) = 400 g
[tex]dA(t)/dt = 50 - \frac{7A(t)}{400} where A(0) = 400[/tex]
b) Solve the differential equation
To solve the equation, we use separation of variables, so
dA(t)/dt = 50 - 7A(t)/400 where A(0) = 400 g
dA(t)/(50 - 7A(t)/400) = dt
Integrating both sides, we have
∫dA(t)/(50 - 7A(t)/400) = ∫dt
-7/400 ÷ -7/400∫dA(t)/(50 - 7A(t)/400) = ∫dt
1/ (-7/400)∫-7/400dA(t)/(50 - 7A(t)/400) = ∫dt
(-400/7)㏑(50 - 7A(t)/400) = t + C
㏑(50 - 7A(t)/400) = -7t/400 + (-7/400)C
㏑(50 - 7A(t)/400) = -7t/400 + C' (C' = (-7/400)C)
taking exponents of both sides, we have
50 - 7A(t)/400 = exp[(-7t/400) + C']
50 - 7A(t)/400 = exp(-7t/400)expC'
[tex]50 - \frac{7A(t)}{400} = e^{-7t/400}e^{C'} \\50 - \frac{7A(t)}{400} = Ae^{-7t/400} A = e^{C'}\\ \frac{7A(t)}{400} = 50 - Ae^{-7t/400} \\A(t) = \frac{400}{7} X 50 - \frac{400}{7} Ae^{-7t/400} \\A(t) = \frac{20000}{7} - \frac{400}{7} Ae^{-7t/400}[/tex]
when t = 0 , A(0) = 400. So,
[tex]A(t) = \frac{20000}{7} - \frac{400}{7} Ae^{-7t/400} \\A(0) = \frac{20000}{7} - \frac{400}{7} Ae^{-7(0)/400}\\A(0) = \frac{20000}{7} - \frac{400}{7} Ae^{0/400}\\A(0) = \frac{20000}{7} - \frac{400}{7} Ae^{0}\\A(0) = \frac{20000}{7} - \frac{400}{7} A\\400 = \frac{20000}{7} - \frac{400}{7} A\\\frac{400}{7} A = 400 - \frac{20000}{7}\\\frac{400}{7} A = \frac{2800}{7} - \frac{20000}{7}\\\frac{400}{7} A = -\frac{17200}{7}\\\\A = -\frac{17200}{7} X \frac{7}{400} \\A = -43[/tex]
So,
[tex]A(t) = \frac{20000}{7} - \frac{400}{7} X -43e^{-7t/400} \\A(t) = \frac{20000}{7} + \frac{17200}{7}e^{-7t/400}[/tex]
c) At 1 p.m., what is the amount of dissolve oxygen in the fish tank.
At 1 p.m, t = 60 min
So, the amount of dissolved oxygen in the fish tank is A(60)
So,
[tex]A(t) = \frac{20000}{7} + \frac{17200}{7}e^{-7t/400}\\A(60) = \frac{20000}{7} + \frac{17200}{7}e^{-7X60/400}\\A(60) = \frac{20000}{7} + \frac{17200}{7}e^{-420/400}\\A(60) = \frac{20000}{7} + \frac{17200}{7}e^{-1.05}\\A(60) = \frac{20000}{7} + \frac{17200}{7} X 0.3499\\A(60) = \frac{20000}{7} + \frac{6018.93}{7} \\A(60) = \frac{26018.93}{7} \\A(60) = 3716.99 g[/tex]
A(60) ≅ 3717 g
A(60) ≅ 3.717 kg
Find the surface area for a sphere with a radius of 10 feet. Round to the nearest whole number.
A.1.256
B.4.189
C.1,089
D.1,568
Answer:
C is my answer
Thank You
Mark me as Brainilest Answer please ty
Please help me with this question
Answer:
An equation is y=-3x+7 (I chose slope-intercept form because they already showed us the slope). When y =13 x=-2
Step-by-step explanation:
plugin 13 for y and subtract 7 from both sides, this lets you get 6=-3x then divide 6 by -3 which makes x=-2
Question 11
A rectangle with a perimeter of 12 inches is enlarged by a scale factor of 3. What is the perimeter of the enlarged
rectangle?
Answer:
The perimeter of the enlarged rectangle is 36 inches.
Step-by-step explanation:
Perimeter of an enlarged figure:
To find the perimeter of an enlarged figure, we multiply the perimeter of the original figure by the scale factor.
In this question:
Perimeter of the original rectangle: 12 inches
Scale factor: 3
Perimeter of the enlarged rectange:
12*3 = 36 inches
For what value of the constant c is the function f continuous on
(−∞,∞) where
f(b) = { cb + 9 if b ≤ 3
c(b)² − 9 if b > 3
9514 1404 393
Answer:
c = 3
Step-by-step explanation:
In order for the function to be continuous at b=3, the left and right limits must be the same. In short, we must have ...
c(3) +9 = c(3²) -9
18 = 6c . . . . . . . . add 9-3c to both sides
3 = c . . . . . . . . . . divide by 6
Function f is continuous when c=3.
Solve (x - 2)^2 - 3 = 1 graphically. That is graph y = (x - 2)^2 - 3 and y = 1 on the same set of axes and find the x-value(s) of any points of intersection. Then use algebraic strategies to solve the equation and verify that your graphical solutions are correct.
Check the attachment(s) for the graphs pertaining to the question
No. 1) Check graph [first attachment]
No. 2) y = (x - 2)^2 - 3, y = 1
(x - 2)^2 - 3 = 1,
(x - 2)^2 = 4
x - 2 = √4, x - 2 = - √4
x = 4, x = 0
Substitute back to determine the respectively y-value:
y = (4 - 2)^2 - 3 = (2)^2 - 3 = 4 - 3 = 1
Check: y = (0 - 2)^2 - 3 = (-2)^2 - 3 = 4 - 3 = 1
So the points of intersection are (4, 1) and (0, 1). According to the graph, that is correct.
William was out at a restaurant for dinner when the bill came. His dinner came to $31. After adding in a tip, before tax, he paid $39.99. Find the percent tip.
Answer: 12.9
Step-by-step explanation: Divide 39.99 by 31.00 you'll get 1.29, but you slide the decimal over and get 12.9
Which is an irrational number Square root of 21 3 5/8 2.4141414 or -13
Answer:
i dont know
Step-by-step explanation:
how many seconds are there in 8 minutes 12seconds
Answer:
1 minute has 60 seconds
therefore 8 minutes will have 60 × 8 seconds = 480 seconds
480 + 12 = 492
hence 8 minutes 12 seconds will have 492 seconds
Answer: 492 seconds
Step-by-step explanation:
1min = 60sec
therefore, 8min 12sec = [8 x 60] + 12
= 480 + 12
= 492 sec
Hope it helped u,
pls mark as the brainliest - Ayaan707 for help :) -
^_^
what is the lcm for 3/4and 1/2
Answer:
1 1/2
Hope that helps!
Step-by-step explanation:
what's 24 -3 (7-5) to the power of two over (+8) (-6) ÷ (+12)?
Answer:
45%
Step-by-step explanation:
45%
What is the difference, in hours and minutes, between these times?
a)
13 40 and 17 15
hours
minutes
b)
11 25 and 14 10
hours
minutes
c)
2:50 am and 7:20 am
hours
minutes
d)
10:35 am and 2:40 pm
hours
minutes
Answer:
a) 3 hrs 35 mins
b) 2 hrs 45 mins
c) 4 hrs 30 mins
d) 4 hrs 5 mins
Step-by-step explanation:
The difference, in hours and minutes, between these times are;
a) 3 hrs 35 mins
b) 2 hrs 45 mins
c) 4 hrs 30 mins
d) 4 hrs 5 mins
What is Algebra?Algebra is the study of abstract symbols, while logic is the manipulation of all those ideas.
The acronym PEMDAS stands for Parenthesis, Exponent, Multiplication, Division, Addition, and Subtraction. This approach is used to answer the problem correctly and completely.
The difference, in hours and minutes, between these times can be calculated as;
a) 13 40 and 17 15
13 :40 - 17 : 15
= 3 hrs 35 mins
b) 11 :25 and 14: 10
11 :25 - 14: 10
= 2 hrs 45 mins
c) 2:50 am and 7:20 am
2:50 am - 7:20 am
= 4 hrs 30 mins
d) 10:35 am and 2:40 pm
10:35 am - 2:40 pm
= 4 hrs 5 mins
More about the Algebra link is given below.
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Help and the question changes when its wrong
For the function f(x)=-7x-5, evaluate f(6)
Answer:
f(x)=-7x-5
f(6)=-7(6)-5
f(6)=-42-5
f(6)=-47
i really really need the answer plz help this is the fourth time im asking this question plz help.
Answer:
5g-4/4your answer right answer
Step-by-step explanation:
we have to find value of g ????
Nine bands are to perform at a weekend festival. Suppose you want to determine how many different ways there are to schedule their appearances. Would you use a combination or a permutation?
Answer:
permutation
Step-by-step explanation:
Analyzing the information in the question above, it is correct to say that it is necessary to use permutation, since the ORDER matters, since there is a need to program the band's appearances.
Permutation can be understood as an arrangement in which n = p, where n is the number of elements in the set and p is the number of available elements.
Therefore, the permutation of nine bands is:
Pn = n!
P9 = 9!
p9 = 362880
Describe the characteristics of metal in which metal converts into sheet.
Answer:
a solid material that is typically hard, shiny, malleable, fusible, and ductile, with good electrical and thermal conductivity ( iron, gold, silver, copper, and aluminum, and alloys such as brass and steel)
Step-by-step explanation:
what is Z x-2, when x=2 and z=2
Answer:
2
Step-by-step explanation:
2x2-2=2
What is the y-intercept of the line with the equation 4y = -3x + 10?
Step-by-step explanation:
Given
4y = - 3x + 10
y = ( - 3x + 10 ) / 4
y = - 3/4 x + 10 / 4
y = - 3/4 x + 5 / 2
Comparing the given equation with y = mx +c Then
y - intercept (c) = 5/2
Hope it will help :)
A curious statistics student cannot get enough statistics, so he decides to analyze the percentage of students sleeping in his statistics class. He discovers that of the 30 students in his class, 47% of the students were asleep at some point during the class period. Assuming the 30 students is less than 10% of all the students taking statistics in his school, and assuming the 30 students in the class were randomly assigned to the class, what model would he use to analyze the percentage of sleeping statistics students
Answer:
c) N(.47, .09)
Step-by-step explanation:
Options to the question are "a) N(.30, .10), b) N(.30, .09). c) N(.47, .09), d) N(.47, .008), e) N(.30, .008)"
Pο = 47% = 0.47
n = 30
Mean = Pο = 0.47
S.D = Pο(1-Pο) / n
S.D = 0.47 * 0.53 / 30
S.D = 0.09
Thus, the percentage of sleeping statistics of students follows a Normal distribution with mean = 0.47 and S..D = 0.09
7.
The expression 25(1.12)m represents a population of spiders after m months. Since a year hus
12 months, 25(1.12)12n represents the population of spiders after n years.
Which expression is approximately equivalent to 25(1.12)1207
A 25(2.44)"
B 25(3.90)"
с 25(13.12)
D 25(13.44)"
Answer:
C
Step-by-step explanation:
You're a contestant on a TV gameshow where you must choose between four identical looking suitcases containing $100, $100, $300, and $400. You start by randomly picking one suitcase. The host then opens the remaining suitcase with the lowest dollar amount. Now, you have the choice to keep your current suitcase or switch to one of the two remaining suitcases. With probability p= 0.7, you keep your original suitcase and open it. Otherwise, you are equally likely to choose either of two the remaining suitcases and open it. You win the money in the suitcase you opened.
Consider these events:
Ai is the event that the first suitcase you choose is worth i dollars.
Hi is the event that the host opens a suitcase worth i dollars.
Wi is the event that you win i dollars.
If you play this game five times, the probability that the event W400 occurs twice in five trials is:_______
Answer:
0.2990 = 29.90%.
Step-by-step explanation:
For each trial, there are only two possible outcomes. Either you win $400, or you do not. Trials are independent. So we use the binomial probability distribution to solve this question.
Binomial probability distribution
The binomial probability is the probability of exactly x successes on n repeated trials, and X can only have two outcomes.
[tex]P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}[/tex]
In which [tex]C_{n,x}[/tex] is the number of different combinations of x objects from a set of n elements, given by the following formula.
[tex]C_{n,x} = \frac{n!}{x!(n-x)!}[/tex]
And p is the probability of X happening.
Probability of winning $400 in a trial:
1/4 probability of choosing the suitcase containing $400, and in this case, 0.7 probability of keeping it.
3/4 probability of choosing another suitcase. Then, 0.3 of 3/4 probability of changing the suitcase, and 0.5 of 0.3 of 3/4 probability of getting the suitcase containing $400. So
[tex]p = \frac{1}{4}*0.7 + \frac{3}{4}*0.3*0.5 = 0.25*0.7 + 0.75*0.15 = 0.2875[/tex]
If you play this game five times, the probability that the event W400 occurs twice in five trials is:_______
This is P(X = 2) when n = 5. So
[tex]P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}[/tex]
[tex]P(X = 2) = C_{5,2}.(0.2875)^{2}.(0.7125)^{3} = 0.2990[/tex]
The probability is 0.2990 = 29.90%.
Calculate the scale factor of ALMN to AOPQ. Enter answer as a whole
number or as a fraction in lowest terms, using the slash mark ( 7 ) for the
fraction bar.
Step-by-step explanation:
the scale factor is 1
1/1
both triangles are similar and the scale factor is 1/1
....................
At The Fencing Center, 60% of the fencers use the foil as their main weapon. We randomly survey 21 fencers at The Fencing Center. We are interested in the numbers that do not use the foil as their main weapon.
Part (a) In words, define the Random Variable X.
the number of fencers that do not use the foil as their main weaponthe different types of weapons the number of fencers at The Fencing Centerthe number of fencers that do use the foil as their main weapon
Part (b) List the values that X may take on.
X = 0, 1, 2, . . ., 60X = 1, 2, 3, . . ., 21 X = 0, 1, 2, . . ., 21X = 1, 2, 3, . . ., 60
Part (c) Give the distribution of X.
X ~
,
Part (d) How many fencers are expected to not use the foil as their main weapon? (Round your answer to the nearest whole number.)
fencers
Part (e) Find the probability that eleven do not use the foil as their main weapon. (Round your answer to four decimal places.)
Part (f) Based on numerical values, would you be surprised if all 21 did not use foil as their main weapon?
Yes. The probability of all 21 fencers not using the foil as their main weapon is small (less than 1%).No. The probability of all 21 fencers not using the foil as their main weapon is large (more than 10%).
Answer:
A.) the number of fencers that do not use the foil as their main weapon
B.) X : 0, 1, 2, 3,..., 21
C.) X ~ p(X) ; 21 ~ 0.4
D.) 21 ~ 0.4
E.) 0.0895
F.) Yes. The probability of all 21 fencers not using the foil as their main weapon is small (less than 1%)
Step-by-step explanation:
A.) since it is reported that 60% of fencers use the foil as their main weapon ;
The random variable (x) : number of fencers that do not use foil as their main weapon ;
( 100% - 60%) = (1 - 0.6) = 0.4
B.) values that X may take on :
Sample size = 21 ;
X : 0, 1, 2,..., 21
The distribution of X
X ~ B ; X ~ p(X) ; 21 ~ 0.4
Part (d) How many fencers are expected to not use the foil as their main weapon?
X * p(x)
21 * 0.4
= 8.4
= 8 (nearest whole number)
Part (e) Find the probability that eleven do not use the foil as their main weapon.
P(x = 11)
Using the binomial probability relation :
P(x =x) = nCx * p^x * (1 - p)^(n - x)
P(x = 11) = 21C11 * 0.4^11 * 0.6^10
P(x = 11) = 0.0895
Part (f) Based on numerical values, would you be surprised if all 21 did not use foil as their main weapon?
P(x = 21) = 21C21 * 0.4^21 * 0.6^0
P(x = 21) = < 0.00001 ( approximately 0)
Hence, based on this very low value which is almost equal to 0 ; it will be surprising if all 21 do not use foil as their main weapon
Find the mean, the median and the mode of 12, 13, 9, 8, 8, 7, 6, 8, 10
Answer:
if I am not mistaken.. the median would be 9 and the the mean is also 9.
Step-by-step explanation:
first you order the numbers from least to greatest and the find with is the middle number to find the median.
6,7,8,8,8,9,10,12,13 (answer: 9)
To find the mean you will add all of the numbers up and then divide that number by the amount of numbers there are.
1) 6+7+8+8+8+9+10+12+13= 81
2) 81 ÷ 9 =9
Answer:
Mean: 9, Median: 8 Mode: 8
Step-by-step explanation:
MEAN: The AVERAGE total of all the values divided by the numbers of values.
6 + 7+ 8 + 8 + 8 + 9 + 10 + 12 + 13 = 81 81/9 (set of #'s)= 9
MEDIAN: The number in the MIDDLE of the list of values.
6, 7, 8, 8, 8, 9, 10, 12, 13 So, the middle value is 8
MODE: The number that appears the most.
6, 7, 8, 8, 8, 9, 10, 12, 13 So, 8 appears 3 times.
Hope this helps!
PLEASE HELP, I WILL MARK BRAINLIEST TO THE ONE WHO ANSWERS FIRST
The perimeter of the base of a square prism is 16cm. The height of the prism is 5 cm. Find the volume of the prism.
(Hint: use the perimeter to find the length of the side)
Answer: Down Below
Step-by-step explanation:
Surface Area(rectangular prism) = 192 cm^2
Area(square) = 16cm^2
Area(square) = LW or S^2
Area = 16cm^2
value digit of 468, 204, 459 , 964, 468
Answer:
964 = 4
204 = 4
459 = 400
468 = 400
Suppose the restaurant’s description of the weights of its hamburgers is true. The dotplot below
shows the distribution of sample means from 100 simulated SRSs of size n = 5 from a normally
distributed population with µ = 8 ounces and σ = 0.54 ounces.
(b) Would it be unusual to get a sample mean of 7.6 oz or less in a sample of size n = 5 from this
population? Explain.
(c) Based on your answer to part (b), is there convincing evidence that the mean weight of
hamburgers at this restaurant is less than 8 oz? Explain.
Answer:
Step-by-step explanation:
It would be unusual because there are only one 7.6 samples out of a total of 100 samples.
Simplify completely and find the restrictions on the variable.
Answer:
[tex]\displaystyle \frac{8}{x - 11}, x \neq 2, 11[/tex]
General Formulas and Concepts:
Pre-Algebra
Order of Operations: BPEMDAS
Brackets Parenthesis Exponents Multiplication Division Addition Subtraction Left to RightAlgebra I
Terms/CoefficientsFactoringAlgebra II
DiscontinuitiesDomain RestrictionsStep-by-step explanation:
Step 1: Define
[tex]\displaystyle \frac{8x - 16}{x^2 - 13x + 22}[/tex]
Step 2: Simplify
[Fraction] Factor numerator: [tex]\displaystyle \frac{8(x - 2)}{x^2 - 13x + 22}[/tex][Fraction] Factor denominator: [tex]\displaystyle \frac{8(x - 2)}{(x - 11)(x - 2)}[/tex][Fraction] Divide: [tex]\displaystyle \frac{8}{x - 11}[/tex]We know that x cannot equal 11, because that would give us a divide by 0 error and we know that x cannot equal 2 because it was canceled out when simplifying.
Twenty-one is greater than the sum of fifteen and two times a number
Answer:
21> 2x+ 15
Step-by-step explanation:
The expression is 21 > 15+ 2x
What is Algebra?A branch of mathematics known as algebra deals with symbols and the mathematical operations performed on them.
Variables are the name given to these symbols because they lack set values.
In order to determine the values, these symbols are also subjected to various addition, subtraction, multiplication, and division arithmetic operations.
Given:
Twenty-one is greater than the sum of fifteen and two times a number
let the number be x.
two times a number = 2x
and, sum of fifteen and two times a number = 15 + 2x
So, Twenty-one is greater than the sum of fifteen and two times a number
21 > 15+ 2x
Hence, the expression is 21 > 15+ 2x.
Learn more about algebra here:
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Elmer is purchasing 2 4/5 pounds of candy that cost $1.85 per pound.
If he pays with $10, how much will he get in change? HELP I WILL MARK BRAINIEST
Answer:
hi
Step-by-step explanation:
Daniel bought 1 pound of jelly beans and 2 pounds of chocolates for $2.00. ... for $1.50. How much would he have to pay on his next trip to the candy store if he bought 1 pound of each of the 4 kinds ... How many are there? Assign ... Multiply each equation by a factor, so that all equations will have the same total price: 3(1j +.