Oil is pumped continuously from a well at a rate proportional to the amount of oil left in the well. Initially there were million barrels of oil in the well; six years later barrels remain.At what rate was the amount of oil in the well decreasing when there were barrels remaining
Answer:
The amount of oil was decreasing at 69300 barrels, yearly
Step-by-step explanation:
Given
[tex]Initial =1\ million[/tex]
[tex]6\ years\ later = 500,000[/tex]
Required
At what rate did oil decrease when 600000 barrels remain
To do this, we make use of the following notations
t = Time
A = Amount left in the well
So:
[tex]\frac{dA}{dt} = kA[/tex]
Where k represents the constant of proportionality
[tex]\frac{dA}{dt} = kA[/tex]
Multiply both sides by dt/A
[tex]\frac{dA}{dt} * \frac{dt}{A} = kA * \frac{dt}{A}[/tex]
[tex]\frac{dA}{A} = k\ dt[/tex]
Integrate both sides
[tex]\int\ {\frac{dA}{A} = \int\ {k\ dt}[/tex]
[tex]ln\ A = kt + lnC[/tex]
Make A, the subject
[tex]A = Ce^{kt}[/tex]
[tex]t = 0\ when\ A =1\ million[/tex] i.e. At initial
So, we have:
[tex]A = Ce^{kt}[/tex]
[tex]1000000 = Ce^{k*0}[/tex]
[tex]1000000 = Ce^{0}[/tex]
[tex]1000000 = C*1[/tex]
[tex]1000000 = C[/tex]
[tex]C =1000000[/tex]
Substitute [tex]C =1000000[/tex] in [tex]A = Ce^{kt}[/tex]
[tex]A = 1000000e^{kt}[/tex]
To solve for k;
[tex]6\ years\ later = 500,000[/tex]
i.e.
[tex]t = 6\ A = 500000[/tex]
So:
[tex]500000= 1000000e^{k*6}[/tex]
Divide both sides by 1000000
[tex]0.5= e^{k*6}[/tex]
Take natural logarithm (ln) of both sides
[tex]ln(0.5) = ln(e^{k*6})[/tex]
[tex]ln(0.5) = k*6[/tex]
Solve for k
[tex]k = \frac{ln(0.5)}{6}[/tex]
[tex]k = \frac{-0.693}{6}[/tex]
[tex]k = -0.1155[/tex]
Recall that:
[tex]\frac{dA}{dt} = kA[/tex]
Where
[tex]\frac{dA}{dt}[/tex] = Rate
So, when
[tex]A = 600000[/tex]
The rate is:
[tex]\frac{dA}{dt} = -0.1155 * 600000[/tex]
[tex]\frac{dA}{dt} = -69300[/tex]
Hence, the amount of oil was decreasing at 69300 barrels, yearly
is 1/3 a rational number?
can rational numbers be negative
six more than the product of a number and 7 is equal to 8 translate the sentence into an equation
Answer:
6+ x 7=8
Step-by-step explanation:
6 more product of a number and it equals 8
Chris is taking 50 pounds of old newspapers to the recycling center. He makes
8 bundles of equal weight. What is a good estimate of the weight of each
bundle?
Answer:
Just over 6 pounds each
Step-by-step explanation:
or exactly 6.25 pounds each
[tex]\huge{\textbf{\textsf{{\color{pink}{An}}{\red{sw}}{\orange{er}} {\color{yellow}{:}}}}}[/tex]
The estimate weight of each bundle is 6 pounds.
exactly it's 6.25 (bcoz 50 ÷ 8 is 6.25)
thanks hope it helpshow do I solve pic rel? Online calculators keep saying the result is -1 but they don't show any steps which is confusing
thx in advance!
Answer:
-1
Step-by-step explanation:
[tex] \sqrt{9 - 4 \sqrt{2} } - 2 \sqrt{2} \\ \\ = \sqrt{8 + 1 - 4 \sqrt{2} } - 2 \sqrt{2} \\ \\ = \sqrt{8 - 4 \sqrt{2} + 1} - 2 \sqrt{2} \\ \\ = \sqrt{ {(2 \sqrt{2}) }^{2} - 2 \times 2 \sqrt{2} \times 1 + {1}^{2} } - 2 \sqrt{2} \\ \\ = \sqrt{( {2 \sqrt{2} - 1)}^{2} } - 2 \sqrt{2} \\ \\ (2 \sqrt{2} - 1) - 2 \sqrt{2} \\ \\ = 2 \sqrt{2} - 1 - 2 \sqrt{2} \\ \\ = - 1[/tex]
If y varies inversely with x
and y is 10 when x is 5,
then what is y when x is 2?
Answer: X = 2 so Y=25, hope this helped!!
Step-by-step explanation:
Expand and simplify (2x - 3)(3x -5)
Answer:
Step-by-step explanation:
Bonjour,
2x*3x =6x²
2x* -5 = -10x
-3 * 3x = -9x
-3*-5 = 15
=>
6x² -10x - 9x +15 = 6x ² -19x +15
Answer:
6x^2 - 19x + 15.
Step-by-step explanation:
(2x - 3)(3x -5)
= 2x(3x - 5) - 3(3x - 5)
= 6x^2 - 10x - 9x + 15
= 6x^2 - 19x + 15.
Can someone help me with this? Thank you so much! I mark as brainliest :)
9514 1404 393
Answer:
x = 9y = 45z = 9 root 2Step-by-step explanation:
In this isosceles right triangle, the acute angles are equal and the side lengths have the ratios 1 : 1 : √2
y° = 90° -45° = 45°
9 : x : z = 1 : 1 : √2 = 9 : 9 : 9√2
x = 9; z = 9√2
Reed has an aquarium that holds 12 gallons of
water. There are approximately 4 liters in one
gallon. Which measurement is closest to the
number of liters in Reed's aquarium?
Answer:
48
Step-by-step explanation:
12*4=48
ames, Sarah, and Danielle are all planting in a community garden. If each of their plots holds 7 rows and 13 columns, how many plants will they be able to grow all together?
Answer:
dude this is easy
Step-by-step explanation:
all you have to do is multiply; 7x13
in this case it equals 91.
=91
-3/16,7/4, -3/8 in order least to greatest
Answer:
-3/8, -3/16, 7/4
Put these in order starting from the smallest
5^2 2^4 3^3 1^8 SOMEONE HELP PLEASE!
Answer:
1⁸,2⁴,5²,3³
Step-by-step explanation:
so its 1,16,25,27
Describe the transformation of f(x) = sin x to g(x) = sin (x-pi/4)
Answer:
A
Step-by-step explanation:
AP EX
The transformation of f(x)=sin(x) to g(x)=sin(x-π/4), means that the function f(x) is shifted to the right by (π/4) units.
What is a Function?A function assigns the value of each element of one set to the other specific element of another set.
The transformation of f(x)=sin(x) to g(x)=sin(x-π/4), means that the function f(x) is shifted to the right by (π/4) units.
Learn more about Function:
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f(x)=- square root x-2. +3
Answer:
Hi, The.
The domain of a function is the set of all possible values for x. The range is all possible values for y.
You should be able to see these pretty easily from the graph. If I understand your function correctly:
f(x) = square root(x+2) - 3
then x cannot be less than -2. Your domain is x > -2. In interval notation [-2,∞)
The lowest value for y is -3 so the range is y > -3. In interval notation [-3,∞)
Hope this helps!
When y= 35 , x= 2 1/2 . If the value of y varies directly with x, what is the value of y when the value of x is 3 1/4?
A. 113 3/4
B. 26 12/13
C. 227 1/2
D. 45 1/2
Answer:
D
Step-by-step explanation:
y is directly proportional with x with a constant value.
The constant value =y ÷ x =35÷2.5 =14
y=14x
y=14×3.25=45.5
EASY 7TH GRADE MATH, WILL GET BRAINLIEST.. AGAIN
Answer:
B. 1/3
Step-by-step explanation:
If we take the fist two boxes on top of the grid, we can divide 7 1/2 by 2 1/2 to find the ratio. In this case, the ratio is 3, meaning that for every cup of sugar their is 3 cups of flour. This means that 1 cup of flour would equal 1/3 cups of sugar.
How many significant figures does 0.396 have?
Answer:
4
Step-by-step explanation:
0 is a significant figure and since there are no 0 in the number after the decimal point its 4 significant figures
Jen used a 15% off coupon on a $250 television. How much did she pay for the television?
37.5
Hope this helps :T
Can someone help ASAP
Answer:
There's only one answer, and that's x=0.
Step-by-step explanation:
Step 1: Simplify both sides of the equation.
3(3x−1)=6x−3
(3)(3x)+(3)(−1)=6x+−3(Distribute)
9x+−3=6x+−3
9x−3=6x−3
Step 2: Subtract 6x from both sides.
9x−3−6x=6x−3−6x
3x−3=−3
Step 3: Add 3 to both sides.
3x−3+3=−3+3
3x=0
Step 4: Divide both sides by 3.
[tex]\frac{3x}{3}[/tex]=[tex]\frac{0}{3}[/tex]
x=0
hope this helps
what is x+19=21 jsjwidhsnwnd
Answer:
x=2
Step-by-step explanation:
x+19=21
subtract 19 so x can be by itself, move it to the 21 side
and subtract21-19=2
Answer:
You solve. for X. The photo is the work and answer
2/3 (x-6) = 6
Pls I need help
Answer:
x=15
Step-by-step explanation:
Answer:
x = 15Explanation:
2/3 (x-6) = 6
2x/3 - 12/3 = 6
(2x-12)/3 = 6
2x-12 = 18
2x = 18+12
2x = 30
x = 15
Can you help me with this question please??
Answer:
D
Step-by-step explanation:
value of each:
A) 100/1000 + 20/1000 + 8/1000 = 128/1000 = 0.128
B) 3/10 = 0.30
C) 7/100 = 0.07
D) 24/1000 = 0.024
line.
4
6 You are given that z>2. Grup
Write an inequality for each expression.
a 2z + 9
b 3(z - 4) C 4 + 2z
d 5(3z-2)
Answer:
a ko ans
= 2×2+9
=4+9
= 13ans
For the following right triangle, find the side length x. Round your answer to the nearest hundredth.
10
14
Answer: [tex]\sqrt{96}[/tex] or [tex]4\sqrt{6}[/tex], if you want the decimal form then its 9.79.
Step-by-step explanation:
14²-10²=96
[tex]\sqrt{96}[/tex] or [tex]4\sqrt{6}[/tex], if you want the decimal form then its 9.79.
Which expressions are equivalent to 4(7/8y-4-3/8y+7)? Choose ALL that apply.
The expressions equivalent to the given expressions are; (2y+12), 4(y/2+3) and 4(y/2-4+7)
What is expression?An algebraic expression consists of unknown variables, numbers and arithmetic operators. It does not contain any equality or inequality symbols.
Given an expression, 4(7/8y-4-3/8y+7)
4(7/8y-4-3/8y+7) = 7/2y-16-3/2y+28
= 1/2(7y-32-3y+56)
= 1/2(4y+24)
= 2y+12
or, 4(1/2y+3) or 4(1/2y-4+7)
Hence, The expressions equivalent to the given expressions are; (2y+12), 4(y/2+3) and 4(y/2-4+7)
For more references on expression, click;
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Can somebody help me?
Answer:I cannot see photo
g Suppose, for simplicity, that three main parts of a laptop are CPU, RAM, and hard drive;so if one of theses components fails, the laptop fails. Assume that the life times of CPU, RAM, and hard drive are exponentially distributed with mean 3 years, 2 years, and 5 years, respectively. If the company that sells these laptops guarantees the replacement of any laptops that fail in the first year, anda replacement costs $500, what would be the average yearly replacement cost
Answer:
The average yearly replacement cost is approximately $32,211,500
Step-by-step explanation:
Exponential Distribution
P(X < x) = 1 - e -x/
[tex]P(X < x) = 1 - e^{\dfrac{-x}{\mu}}[/tex]
For the CPU, μ = 3 years
The probability that a CPU fails in less than 1 year is therefore;
P(C) = [tex]P(X < 1) = 1 - e^{\dfrac{-1}{3}} \approx 0.2835[/tex]
For the RAM, μ = 2 years
The probability that a RAM fails in less than 1 year is therefore;
P(R) = [tex]P(X < 1) = 1 - e^{\dfrac{-1}{2}} \approx 0.3935[/tex]
For the hard drive, μ = 5 years
The probability that a hard drive fails in less than 1 year is therefore;
P(H) = [tex]P(X < 1) = 1 - e^{\dfrac{-1}{5}} \approx 0.1813[/tex]
The probability that either a CPU, or a RAM or a hard drive fails in 1 year so that a replacement is required, P(C ∪ R ∪ H), is given as follows;
P(C ∪ R ∪ H) = P(C) + P(R) + P(H) - P(C∩R) - P(C∩H) - P(R∩H) + P(C∩R∩H)
∴ P(C ∪ R ∪ H) = 0.2835 + 0.3935 + 0.1813 - (0.2835 × 0.3935) - (0.2835 × 0.1813) -(0.3935 × 0.1813) + (0.2835 × 0.3935 × 0.1813) ≈ 0.64423
∴ P(C ∪ R ∪ H) ≈ 0.64423
There is a 0.64423 chance that a laptop will require replacement
For 100,000 laptops sold a year and a replacement cost of $500 per laptop, we have;
The average yearly replacement cost, 'Cost' is given as follows;
Cost = 500 × 100,000 × 0.64423 = 32,211,500
The average yearly replacement cost, Cost ≈ $32,211,500
A business suit that is regularly $250 is put on sale. They are reducing the price by
30% each day. How much will the suit be worth in 10 days?
Answer:
On the 10th day, the suit should cost around $11.38.
Step-by-step explanation:
It was a long process. Not sure if it is right because that price drop is very drastic, but these math problems are always extreme. LOL
Good Luck!!
I NEED HELP FAST ASAP PLS
Answer:
The answer is 25 plants because all the frequencies add up to 25. While this graph could represent plants when they’re growing, all bars would be the same length though as all plants would hit a certain height.
B) Interval 150-155 has the highest frequency as 8 plants are 150-155cm.
Step-by-step explanation:
Which situations are BEST modeled by a linear function? es A) A monthly gym membership fee. B) The cost of milk by the gallon. 0) The price of pears by the pound D) The interest rate on a car lone. E) The half-life of a radiative material.
Answer:
B) The cost of milk by the gallon.
C) The price of pears by the pound.
Step-by-step explanation:
A linear function is one that both the dependent and independent variables increases or decreases proportionally.
Thus from the given options:
i. If the gallons of milk increase, then the cost of milk also would increase proportionally. A decrease in the gallons of milk would also reduce the cost of milk.
ii. An increase in the pounds of the pearls would cause an increase in the price of the pearls. Also, a decrease in the pounds of pearls would reduce the price of the pearls.
Thus, the answers to the question are options B and C.
Answer:
The other guy is correct however he missed one
The Answer is actually A, B, C
Step-by-step explanation:
I took the test on Usa test prep.