Answers
Answer:
[tex]\textsf{i)} \quad \text{T} &=2 \pi r^2 + \dfrac{26}{r}[/tex]
ii) radius = 1.27 cm (3 sf)
height = 2.55 cm (3 sf)
Step-by-step explanation:
[tex]\text{Volume of a cylinder}=\pi r^2 h \quad \text{(where r is radius and h is height)}[/tex]
Given volume = 13 cm³, rewrite the equation making h the subject:
[tex]\implies 13=\pi r^2 h[/tex]
[tex]\implies h=\dfrac{13}{\pi r^2}[/tex]
Substitute found expression for h into the Surface Area equation to find the expression for the total surface area, T:
[tex]\begin{aligned}\text{Surface Area of a cylinder} & =2 \pi r^2 + 2 \pi r h\\\implies \text{Surface Area} & =2 \pi r^2 + 2 \pi r \left(\dfrac{13}{\pi r^2}\right)\\& =2 \pi r^2 + \dfrac{26 \pi r}{\pi r^2}\\ \implies \text{T} &=2 \pi r^2 + \dfrac{26}{r}\end{aligned}[/tex]
To find the radius of the minimum surface area, differentiate T with respect to r:
[tex]\begin{aligned}\text{T}& =2 \pi r^2 +26r^{-1}\\\implies \dfrac{dT}{dr} & =(2)2 \pi r^{(2-1)}+(-1)26r^{(-1-1)}\\ & =4 \pi r-26r^{-2}\\ & =4 \pi r-\dfrac{26}{r^2}\\ & = \dfrac{4 \pi r^3-26}{r^2} \end{aligned}[/tex]
Set it to zero, and solve for r:
[tex]\begin{aligned}\dfrac{dT}{dr} & = 0 \\\implies \dfrac{4 \pi r^3-26}{r^2} & = 0 \\\impliles 4 \pi r^3-26 & = 0 \\4 \pi r^3 & = 26 \\r^3 & = \dfrac{13}{2 \pi} \\r & = \sqrt[3]{\dfrac{13}{2 \pi}} \end{aligned}[/tex]
To find the height, substitute the found value of r into the equation for height (found previously):
[tex]\begin{aligned}h & =\dfrac{13}{\pi r^2} \\\implies h & =\dfrac{13}{\pi \left(\sqrt[3]{\dfrac{13}{2 \pi}}\right)^2} \\& =2.548499134\end{aligned}[/tex]
Therefore,
radius = 1.274249567... = 1.27 cm (3 sf)height = 2.548499134... = 2.55 cm (3 sf)Related Questions
Translate into an equation.
The sum of seven and a number, x, is five.
Answers
Answer:
x + 7 = 5
Step-by-step explanation:
I think this should be an equation I’m in 7th and I am learning these again so it should be an equation.
find the domain and range
Answers
Answer:
Domain: all real numbers (all reals)
Range: y> OR EQUAL TO -2
Step-by-step explanation:
Hope this helps! ;-)
The volume of a right cone is 168π units^3. If its diameter measures 12 units, find its height
Answers
Answer:
14 unitsStep-by-step explanation:
In the question, it is given that a right cone has a diameter of 12 units and volume of 168π units³ and we have to find the height of the cone.
[tex] \: [/tex]
To Find the height of the cone, we must know this formula :
[tex]\\{\longrightarrow{ \qquad{\underline{\boxed {\pmb{\frak { \dfrac{1}{3} \: \pi r^2h ={ Volume_{(cone) }}}}}}}}} \\ \\[/tex]
Where,
r refers to the radius of the cone. Here, the diameter is 12, Therefore the radius will be 6 units.h refers to the height of the cone.Now, we will substitute the values in the formula :
[tex]\\ {\longrightarrow{ \qquad{{ {\pmb{\sf { \dfrac{1}{3} \times \pi \times (6)^2 \times h = 168 \pi}}}}}}} \\ \\[/tex]
Cancelling π from both sides we get :
[tex]\\ {\longrightarrow{ \qquad{{ {\pmb{\sf { \dfrac{1}{3} \times \cancel\pi \times 36 \times h = 168 \cancel\pi}}}}}}} \\ \\[/tex]
[tex]\\ {\longrightarrow{ \qquad{{ {\pmb{\sf { \dfrac{1}{3} \ \times 36 \times h = 168 }}}}}}} \\ \\[/tex]
[tex]\\ {\longrightarrow{ \qquad{{ {\pmb{\sf { \dfrac{36}{3} \times h = 168 }}}}}}} \\ \\[/tex]
[tex]\\ {\longrightarrow{ \qquad{{ {\pmb{\sf { 12 \times h = 168 }}}}}}} \\ \\[/tex]
[tex]\\ {\longrightarrow{ \qquad{{ {\pmb{\sf { h = \frac{168}{12} }}}}}}} \\ \\[/tex]
[tex]\\{\longrightarrow{ \qquad{\underline{\boxed {\pmb{\frak { h ={14 }}}}}}}} \\ \\[/tex]
Therefore,
The height of the cone is 14 units .let y= -11sin(4x-8)
what is the amplitude?
what is the period?
what is the phase shift?
Answers
If the equation is y = - 11sin(4x - 8). Then amplitude will be 11, the time period is 4, and the phase difference is 8.
What is a sinusoidal Function?It is a function that repeats itself in a particular time interval.
The sinusoidal function is given as
y= |A| sin(ωx - Φ) ...1
Where A is amplitude, ω is the time period, and Φ is the phase difference.
The equation is given below.
y = -11 sin(4x - 8) ...2
Comparing the equations 1 and 2, then we have
Amplitude will be 11, the time period is 4, and the phase difference is 8.
More about the sine function link is given below.
https://brainly.com/question/3876065
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When you have your final draft, you are ready to_________your essay using the work processor.
A. Peer edit
B. Publish
C. Revise
D. Prewrite
Answers
Answer:
C) Revise
Step-by-step explanation:
A final draft needs to be revised before it can be published
Which polynomial expression is equal to (a + 3)(a − 3)(a² + 9)?
Answers
Answer:
a⁴ - 81
Step-by-step explanation:
Identity applied :
(a + b)(a - b) = a² - b²
Simplifying :
(a + 3)(a − 3)(a² + 9)(a² - 9)(a² + 9)a⁴ - 81find the area of rectangle hall of length 64 5/7 m and breadth 23 3/8 m
Answers
The area of the rectangle hall is 1512.7 square m if the length 64 5/7 m and breadth 23 3/8 m
What is the area of the rectangle?It is defined as the area occupied by the rectangle in two-dimensional planner geometry.
The area of a rectangle can be calculated using the following formula:
Rectangle area = length x width
The length of the rectangle = [tex]64\dfrac{5}{7}[/tex] m = 453/7 m
The breadth of the rectangle = [tex]23\dfrac{3}{8}[/tex] m = 187/8 m
The area of the rectangle hall:
= (453/7)(187/8) = 1512.69 ≈ 1512.7square m
Thus, the area of the rectangle hall is 1512.7 square m if the length 64 5/7 m and breadth 23 3/8 m
Learn more about the rectangle here:
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CAN ANYONE PLEASE HELP!’
Answers
Answer:
130 cm³
Step-by-step explanation:
Volume of the pyramid = 1/3 × base area × height
Calculating base area;
Area = length × width
= 8 × 7
= 56 cm²
Now, Volume = ⅓ × 56 × 7
= ⅓ × 392
= 130.6 cm³.
Figure out this equation I already attempted to do it multiple times
Answers
Here's the link to the answer:
https://riverside.rocks/index.php
A line passes through the point (-2, -9) and has a slope of 8
Answers
Step-by-step explanation:
[tex]y - y_1 = m.(x - x_1)[/tex]
[tex]y - ( - 9) = 8.(x - ( - 2))[/tex]
[tex]y = 8x + 16 - 9[/tex]
[tex]y = 8x + 7[/tex]
Answer:
y = 8x + 7
Step-by-step explanation:
We are given that a line contains the point (-2, -9), and a slope of 8
We want to write the equation of this line
There are multiple ways to write the equation of the line:
Slope-intercept form, written as y=mx+b where m is the slope and b is the y interceptStandard form, written as ax+by=c, where a, b, and c are free integer coefficients, but a and b cannot be zero and a cannot be negativePoint-slope form, written as [tex]y-y_1=m(x-x_1)[/tex], where m is a slope and [tex](x_1, y_1)[/tex] is a pointThe most common of these 3 methods is slope-intercept form, so let's write our equation this way
As we are already given the slope, we can immediately plug that into our formula for m
Replace m with 8:
y=8x+b
Now we need to find b
As the equation passes through (-2, -9), we can use its values to help solve for b
Substitute -2 as x and -9 as y:
-9 = 8(-2) + b
Multiply
-9 = -16 + b
Add 16 to both sides
7 = b
Substitute 7 as b.
y = 8x + 7
Topic: finding the equation of the line
See more here: https://brainly.com/question/7358459
...........................................................
Answers
Answer:
55
Step-by-step explanation:
Whats the difference between 16x + 5 and 4x + 5
Answers
Difference Between 16x+5 and 4x+5
16x+5-4x+5
C.L.T (Collect Like Terms)
16x-4x+5+5
12x+10
The question is attached.
Answers
Answer:
A
Step-by-step explanation:
Please see attached, I have colour coded for your convenience
Can someone help me with this please?
Answers
The final matrix will be as follows [tex]\rm D-C=\left[\begin{array}{ccc}12&-2&3\\3&1&-2\\\end{array}\right][/tex]
What are matrices?A matrix is a rectangular array or table of numbers, symbols, or expressions arranged in rows and columns in mathematics.
The calculation of the given matrix is as follows:-
[tex]\rm D-C= \left[\begin{array}{ccc}13&2&-5\\6&-4&0\\\end{array}\right] - \left[\begin{array}{ccc}1&4&-8\\3&-5&2\\\end{array}\right] \\[/tex]
[tex]\rm D-C= \left[\begin{array}{ccc}(13-1)&(2-4)&(-5+8)\\(6-3)&(-4+5)&(0-2)\\\end{array}\right][/tex]
[tex]\rm D-C=\left[\begin{array}{ccc}12&-2&3\\3&1&-2\\\end{array}\right][/tex]
Hence the final matrix will be as follows [tex]\rm D-C=\left[\begin{array}{ccc}12&-2&3\\3&1&-2\\\end{array}\right][/tex]
To know more about matrix follow
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Which of the following does NOT contribute to global warming?
A. Oil
B. Gas
C. Nuclear power
D. Coal
Answers
Answer:
D. Coal.
Step-by-step explanation:
Doesn’t really affect the earth in any way.
The diagram shows the locations of Cody and Reese after running different directions from a tree. How far did Cody run?
Answers
Answer:
very very far indead he ran and ran without stopping
help me pleaseeeeeeeeeeeeeeeeee
Answers
Answer:
Step-by-step explanation:
Volume
V = w h l
V = 2*15*13
V = 390 ft^3
-------------------------
Surface area
SA = b*h
SA = 15*13
SA = 195
-------------------------
b) Surface area
C) Volume
Can someone answer theese 3 questions
Answers
Answer:
Which three questions?
Step-by-step explanation:
I've answered this first question, I guess I need two more...
Select all the correct measures of center and variation for the following data set.
10, 20, 31, 17, 18, 5, 22, 25, 14, 43
First quartile = 12
IQR = 11
Median = 19
Third quartile = 25
MAD = 7
Answers
Answer:
Median = 19
IQR = 11
Third quartile = 25
Step-by-step explanation:
Just caculate it...
5 STARS FOR A CORRECT ANSWER IMAGE ATTACHED can anyone please answer this or how i find the weighted mean?
Answers
So, basically this is the formula to calculate weight mean.
Thank you.
This morning, Manuel's car had 27.24 gallons of fuel. Now, 5.7 gallons are left. How much fuel did Manuel use?
gallons
Answers
Answer:
21.54
Step-by-step explanation:
27.24 - 5.7
= 21.54
what is the maximum monthly credit obligation that she has
Answers
Answer:
$373.50
Step-by-step explanation:
Her monthly maximum obligation should be 15% of Bridgette's take-home pay of $2490.
$2490×15% = $373.50
What is the probability that a registered voter voted in the election?
Answers
Answer:
0.4714, a simplified 47%
Step-by-step explanation:
:)
if the circle passing through the point (-1,0) touches the y- axis at (0,2) then what's the equation of the circle?
Answers
Answer:
(x +2.5)² +(y -2)² = 6.25
Step-by-step explanation:
A radius of a circle is perpendicular to the tangent line at the point of tangency. This means the center of the circle lies on the horizontal line through the point (0, 2), which is on the vertical tangent x=0 (the y-axis).
The center of a circle lies on the perpendicular bisector of any chord, so the perpendicular bisector of the given two points will pass through the circle center.
__
equation of the chord bisectorThe slope of the chord between the given points is found using the slope formula:
m = (y2 -y1)/(x2 -x1)
m = (2 -0)/(0 -(-1)) = 2 ⇒ perpendicular has slope -1/2
The midpoint of the chord is ...
M = (A +B)/2 = ((0, 2) +(-1, 0))/2 = (-1, 2)/2 = (-1/2, 1)
The point-slope form of the perpendicular through the midpoint of the chord is ...
y -1 = -1/2(x -(-1/2))
__
center of the circleFor y = 2, the x-value is ...
2 -1 = -1/2(x +1/2)
-2 = x +1/2 . . . . . . multiply by -2
-2.5 = x . . . . . . . subtract 1/2
The circle center is (-2.5, 2), and the radius is 2.5 (distance from center to y-axis).
__
equation of the circleThe equation can be written as ...
(x -h)² +(y -k)² = r² . . . . . . circle with center (h, k) and radius r
(x -(-2.5))² +(y -2)² = 2.5²
(x +2.5)² +(y -2)² = 6.25
Mr. Sanchez is pulling his luggage across the airport floor. He applies a 22-newton force to the handle of the bag when the bag makes a 72-degree angle with the floor. Find the magnitudes of the horizontal and vertical components of the force. Round your answers to the nearest tenth.
Answers
Brainly for the one who help me
Answers
Answer:
prior to
Step-by-step explanation:
what set of data corresponds to the dot plot
Answers
At the school track meet, Dita ran 100 meters at a rate of 6.25 meters per second.
Time = StartFraction distance Over rate EndFraction
How long did it take Dita to finish the race?
16 seconds
93.75 seconds
106.25 seconds
625 seconds
Answers
original equation
[tex]v=\frac{d}{t}[/tex]
solve for t
[tex]t=\frac{d}{v}\\\\t=\frac{100}{6.25} \\\\t=16[/tex]
It took Dita 16 seconds to finish the race
Answer:
a
Step-by-step explanation:
aaaaaaa
its a
16 seconds
given that (3x+2) is a factor of 3x^3+bx^2-3x-2. find the value of b?
Answers
Answer:
[tex]b = 2[/tex].
Step-by-step explanation:
By the factor theorem, if a monomial of the form [tex](x - a)[/tex] is a factor of the polynomial [tex](3\, x^{3} + b\, x^{2} - 3\, x - 2)[/tex], then substituting in [tex]x = a[/tex] would set this polynomial to [tex]0[/tex].
Notice that in the factor theorem, the coefficient of [tex]x[/tex] in [tex](x - a)[/tex] is [tex]1[/tex], and the sign in front of the constant [tex]a[/tex] is a minus sign. Rewrite the given factor [tex](3\, x + 2)[/tex] in this form to find the value of [tex]a\![/tex]:
[tex]\begin{aligned}& (3\, x + 2) \\ =\; & 3\, (x + (2/3)) \\ =\; & 3\, (x - \underbrace{(-2/3)}_{a}) \end{aligned}[/tex].
Thus, [tex]x = (-2/3)[/tex] should set the polynomial [tex](3\, x^{3} + b\, x^{2} - 3\, x - 2)[/tex] to [tex]0[/tex]:
[tex]\begin{aligned} & (3\, x^{3} + b\, x^{2} - 3\, x - 2) \\ =\; & 3\times (-2/3)^{3} + b\times (-2/3)^{2} - 3 \times (-2/3) - 2 \\ =\; & -3\times (2/3)^{3} + b\times (2/3)^{2} + 3 \times (2/3) - 2 \\ =\; & -\frac{8}{9} + \frac{4\, b}{9} + 2 - 2 \\ =\; & \frac{-8 + 4\, b}{9}\end{aligned}[/tex].
Set this expression to [tex]0[/tex] and solve for [tex]b[/tex]:
[tex]\displaystyle \frac{-8 + 4\, b}{9} = 0[/tex].
[tex]b = 2[/tex].
What is the range of the following relation?
Answers
Answer:
Y less than or equal to zero
Step-by-step explanation:
The graph shows that its moving downwards, therefore the Y value is decreasing..
