A solid is formed by adjoining two hemispheres to the ends of a right circular cylinder. The total volume of the solid is 10 cubic centimeters. Find the radius of the cylinder that produces the minimum surface area. (Round your answer to two decimal places.)

Answers

Answer 1

Answer:

[tex]r = 1.34[/tex]

Step-by-step explanation:

Given

Solid = Cylinder + 2 hemisphere

[tex]Volume = 10cm^3[/tex]

Required

Determine the radius (r) that minimizes the surface area

First, we need to determine the volume of the shape.

Volume of Cylinder (V1) is:

[tex]V_1 = \pi r^2h[/tex]

Volume of 2 hemispheres (V2) is:

[tex]V_2 = \frac{2}{3}\pi r^3 +\frac{2}{3}\pi r^3[/tex]

[tex]V_2 = \frac{4}{3}\pi r^3[/tex]

Volume of the solid is:

[tex]V = V_1 + V_2[/tex]

[tex]V = \pi r^2h + \frac{4}{3}\pi r^3[/tex]

Substitute 10 for V

[tex]10 = \pi r^2h + \frac{4}{3}\pi r^3[/tex]

Next, we make h the subject

[tex]\pi r^2h = 10 - \frac{4}{3}\pi r^3[/tex]

Solve for h

[tex]h = \frac{10}{\pi r^2} - \frac{\frac{4}{3}\pi r^3 }{\pi r^2}[/tex]

[tex]h = \frac{10}{\pi r^2} - \frac{4\pi r^3 }{3\pi r^2}[/tex]

[tex]h = \frac{10}{\pi r^2} - \frac{4r }{3}[/tex]

Next, we determine the surface area

Surface area (A1) of the cylinder:

Note that the cylinder is covered by the 2 hemisphere.

So, we only calculate the surface area of the curved surface.

i.e.

[tex]A_1 = 2\pi rh[/tex]

Surface Area (A2) of 2 hemispheres is:

[tex]A_2 = 2\pi r^2+2\pi r^2[/tex]

[tex]A_2 = 4\pi r^2[/tex]

Surface Area (A) of solid is

[tex]A = A_1 + A_2[/tex]

[tex]A = 2\pi rh + 4\pi r^2[/tex]

Substitute [tex]h = \frac{10}{\pi r^2} - \frac{4r }{3}[/tex]

[tex]A = 2\pi r(\frac{10}{\pi r^2} - \frac{4r }{3}) + 4\pi r^2[/tex]

Open bracket

[tex]A = \frac{2\pi r*10}{\pi r^2} - \frac{2\pi r*4r }{3} + 4\pi r^2[/tex]

[tex]A = \frac{2*10}{r} - \frac{2\pi r*4r }{3} + 4\pi r^2[/tex]

[tex]A = \frac{20}{r} - \frac{8\pi r^2 }{3} + 4\pi r^2[/tex]

[tex]A = \frac{20}{r} + \frac{-8\pi r^2 }{3} + 4\pi r^2[/tex]

Take LCM

[tex]A = \frac{20}{r} + \frac{-8\pi r^2 + 12\pi r^2}{3}[/tex]

[tex]A = \frac{20}{r} + \frac{4\pi r^2}{3}[/tex]

Differentiate w.r.t r

[tex]A' = -\frac{20}{r^2} + \frac{8\pi r}{3}[/tex]

Equate A' to 0

[tex]-\frac{20}{r^2} + \frac{8\pi r}{3} = 0[/tex]

Solve for r

[tex]\frac{8\pi r}{3} = \frac{20}{r^2}[/tex]

Cross Multiply

[tex]8\pi r * r^2 = 20 * 3[/tex]

[tex]8\pi r^3 = 60[/tex]

Divide both sides by [tex]8\pi[/tex]

[tex]r^3 = \frac{60}{8\pi}[/tex]

[tex]r^3 = \frac{15}{2\pi}[/tex]

Take [tex]\pi = 22/7[/tex]

[tex]r^3 = \frac{15}{2 * 22/7}[/tex]

[tex]r^3 = \frac{15}{44/7}[/tex]

[tex]r^3 = \frac{15*7}{44}[/tex]

[tex]r^3 = \frac{105}{44}[/tex]

Take cube roots of both sides

[tex]r = \sqrt[3]{\frac{105}{44}}[/tex]

[tex]r = \sqrt[3]{2.38636363636}[/tex]

[tex]r = 1.33632535155[/tex]

[tex]r = 1.34[/tex] (approximated)

Hence, the radius is 1.34cm

Answer 2

The radius of the cylinder that produces the minimum surface area is 1.34cm and this can be determined by using the formula area and volume of cylinder and hemisphere.

Given :

A solid is formed by adjoining two hemispheres to the ends of a right circular cylinder. The total volume of the solid is 10 cubic centimeters.

The volume of a cylinder is given by:

[tex]\rm V = \pi r^2 h[/tex]

The total volume of the two hemispheres is given by:

[tex]\rm V' = 2\times \dfrac{2}{3}\pi r^3[/tex]

[tex]\rm V' = \dfrac{4}{3}\pi r^3[/tex]

Now, the total volume of the solid is given by:

[tex]\rm V_T = \pi r^2 h+\dfrac{4}{3}\pi r^3[/tex]

Now, substitute the value of the total volume in the above expression and then solve for h.

[tex]\rm 10 = \pi r^2 h+\dfrac{4}{3}\pi r^3[/tex]

[tex]\rm h = \dfrac{10}{\pi r^2}-\dfrac{4r}{3}[/tex]

Now, the surface area of the curved surface is given by:

[tex]\rm A = 2\pi r h[/tex]

Now, the surface area of the two hemispheres is given by:

[tex]\rm A'=2\times (2\pi r^2)[/tex]

[tex]\rm A'=4\pi r^2[/tex]

Now, the total area is given by:

[tex]\rm A_T = 2\pi rh+4\pi r^2[/tex]

Now, substitute the value of 'h' in the above expression.

[tex]\rm A_T = 2\pi r\left(\dfrac{10}{\pi r^2}-\dfrac{4r}{3}\right)+4\pi r^2[/tex]

Simplify the above expression.

[tex]\rm A_T = \dfrac{20}{r} + \dfrac{4\pi r^2}{3}[/tex]

Now, differentiate the total area with respect to 'r'.

[tex]\rm \dfrac{dA_T}{dr} = -\dfrac{20}{r^2} + \dfrac{8\pi r}{3}[/tex]

Now, equate the above expression to zero.

[tex]\rm 0= -\dfrac{20}{r^2} + \dfrac{8\pi r}{3}[/tex]

Simplify the above expression in order to determine the value of 'r'.

[tex]8\pi r^3=60[/tex]

r = 1.34 cm

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90

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[tex]\mathbf{2(43 - 1) + 6}\\\\\mathbf{= 2(\boxed{\bf 42}) + 6}\\\\\mathbf{= \boxed{\bf 84} + 6}\\\\\mathbf{= 90}\\\\\\\\\\\huge\textbf{Therefore, your answer is: \boxed{\mathsf{90}}}\huge\checkmark[/tex]

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Match each equation with its graph

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Answer:

The first graph would be y=5x+2

The second graph would be y=3x+3

The third graph would be y=2x+3

Step-by-step explanation:

First Graph: The x-intercept would be (-0.4, 0). The y-intercept would be (0, 2). The line in the graph goes through both of the points.

Second Graph: x = -1.

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I need help on this angle measurement paper​

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Wait......What.....Isssssss.....that!?!??

Which of the following describes the roots of the polynomial function f (x) = (x + 2) squared (x minus 4) (x + 1) cubed?
–2 with multiplicity 2, 4 with multiplicity 1, and –1 with multiplicity 3
–2 with multiplicity 3, 4 with multiplicity 2, and –1 with multiplicity 4
2 with multiplicity 2, –4 with multiplicity 1, and 1 with multiplicity 3
2 with multiplicity 3, –4 with multiplicity 2, and 1 with multiplicity 4

Answers

Answer:

A

Step-by-step explanation:

[tex]f(x) = (x + 2)^2(x-4)(x + 1)^3[/tex]

x+2=0

x+2-2=0-2

x=-2.....(x+2) was squared...exponent of 2...multiplicity of 2

x-4=0

x-4+4=0+4

x=4....(x-4) has no visible exponent which means it is essentially to the power of 1...multiplicity of 1

x+1=0

x+1-1=0-1

x=-1....(x+1) was cubed...exponent was 3...multiplicity of 3

The roots and their respective multiplicity are –2 with multiplicity 2, 4 with multiplicity 1, and –1 with multiplicity 3 thus option (A) is correct.

What are the roots of an equation?

The roots of an equation are the solution of that equation, since an equation consists of hidden values of the variable so to determine them by different processes and then the resultant is called roots.

For example root of x -4 = 0 is x = 4 so 4 will be the only root of this linear equation.

As per the given function,

f(x) = (x + 2)²(x - 4)(x + 1)³

The roots are the points at which the value of the function is zero.

f(x) = 0

(x + 2)²(x - 4)(x + 1)³ = 0

(x + 2)² = 0

x = -2 (with a multiplicity of 2)

(x - 4) = 0

x = 4  (with a multiplicity of 1)

(x + 1)³ = 0

x = -1  (with a multiplicity of 3)

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Answers

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Answer:

2/3

Step-by-step explanation:

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y adds by 3's: 0 3 6 9...

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Answer: What is the value of k in the equation k/3-5=34

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Answer:

k = 117

Step-by-step explanation:

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the answer choices are

Answers

here it is, hope i helped :)

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Answer:

6 2/6 -3 2/8

Step-by-step explanation:

6*6=36

36+2=38

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8*3=24

24+2=26

so it becomes 26/8

for same denominator *ply 38/6 with 8 &26/8 with 6

it will become: 304-156/48

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Answers

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Step-by-step explanation:

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Step-by-step explanation:

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Answers

Answer:

1

Step-by-step explanation:

There are 1/3•9=3, so 3÷1/3=9.9-9=00+1=1

The value of the expression 9 - 3/1/3 + 1 will be 1.

What is Mathematical  expression?

Mathematical expression is defined as the collection of the numbers variables and functions by using operations like addition, subtraction, multiplication, and division.

Given that;

The expression is,

⇒ 9 - 3/1/3 + 1

Now,

Solve the expression as;

The expression is,

⇒ 9 - 3/1/3 + 1

⇒ 9 - 3 × 3 + 1

⇒ 9 - 9 + 1

⇒ 1

Thus, The value of the expression 9 - 3/1/3 + 1 will be 1.

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Answers

Answer:

[tex]m=\frac{-14}{11}[/tex]

General Formula and Concepts:

Pre-Algebra

Order of Operations: BPEMDAS

Algebra I

Slope Formula: [tex]m=\frac{y_2-y_1}{x_2-x_1}[/tex]

Step-by-step explanation:

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Point (-2, 9)

Step 2: Find slope m

Substitute:                    [tex]m=\frac{9+5}{-2-9}[/tex]Add/Subtract:               [tex]m=\frac{14}{-11}[/tex]Rewrite:                        [tex]m=\frac{-14}{11}[/tex]


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Answer:

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Step-by-step explanation:

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Answer:

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Answer:

linear

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Answers

The spinner is divided into 10 equal sections.

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D) spinning a number greater than 8

E) spinning a number less than 8

Answer:

Options A, B & D are correct

Step-by-step explanation:

From the image attached, we can see that the total number on the spinner is 10.

Now, we want to find which event has theoretical probability of exactly 1/5

Option A: spinning a number less than 3 means we get 1 or 2 which is 2 numbers.

Thus; probability = 2/10 = 1/5.

This option is true

Option B: spinning a 4 or 5 means 2 numbers.

Thus; probability = 2/10 = 1/5.

This option is true

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Thus, probability = 5/10 = 1/2

This option is wrong.

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Thus, probability = 2/10 = 1/5

This option is correct

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1,2,3,4,5,6,7. That's a total of 7 numbers.

Probability = 7/10

Thus, this option is wrong.

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Step-by-step explanation:

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66.666%

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Step-by-step explanation:

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Answers

Answer:

The probability is [tex]P(X = 0) =  0.6997[/tex]

Step-by-step explanation:

From the question we are told that

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Generally the Poisson distribution constant  [tex]\lambda[/tex] is mathematically represented as

        [tex]\lambda = \frac{1}{\mu }[/tex]

=>     [tex]\lambda = \frac{1}{2.8 }[/tex]

=>     [tex]\lambda = 0.3571[/tex]

Generally the probability distribution for Poisson distribution is mathematically represented as  

     [tex]P(X = x) =  \frac{(\lambda t)^x e^{-t \lambda}}{x!}[/tex]

Here  t =  1 day

Generally the probability  that no babies are born today is mathematically represented as

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4020

Step-by-step explanation:

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Answers

Answer:

one solution

x=9

Step-by-step explanation:

10x+37=14x+1

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36=4x

x=9

Answer:

X = 9

It has ONE SOLUTION

Step-by-step explanation:

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10x + 37 = 14x + 1 (combine like terms)

-4x = -36 (subtraction property)

x = 9

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Equation:
Solution:

Answers

Answer:

11

Step-by-step explanation:

Equation: 8x - 12 = 76

Add 12 to both sides

8x = 88

Divide both sides by 8

x = 11

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x/4-6=2 simplify the following two step equation

Answers

Answer:

First, collect the like terms by one side

x/4=2+6

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Then, criss-cross it, which means multiply 4 with 8

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Step-by-step explanation:

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Answer:

0.49 49

=

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99

Step-by-step explanation:

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XXX

x

=

0.49

¯¯¯¯

49

then

XXX

100

x

=

49.49

¯¯¯¯

49

and

XXX

99

x

=

100

x

x

=

49

XXX

x

=

49

99

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The height would be 42 meters

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the total Hight would be 42 meters

Step-by-step explanation:

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a recipe for cooking turkey says to allow 15 minute cooking for each pound of turkey and to add 5 minutes additional cooking time per pound if the turkey is stuffed. this turkey weighs 15 pounds and will be stuffed. after cooking, the turkey will need 1/2 hour wait time for cooling and carving. what is the independent and dependent

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The doctor had the opinion about the boy that it world

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Answers

Answer:

the answer is b

Step-by-step explanation:

What is the absolute value of 2-9i

Answers

Answer:

so we get as,

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so we get as,

|y| = 2-9i

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so we get as,

|y|=

√81+4=√85

so the value is √85

Example:

| − 2 − i | = √ 5

Explanation:

Absolute value of a complex number  a + i b  is written as  | a + i b |  and its value as  √a 2 + b 2 .  

Hence, absolute value of  − 2 − i  is  √ ( − 2 ) 2 + ( − 1 ) 2 = √ 4 + 1 = √ 5 .

Step-by-step explanation:

11 ÷ 924 in long division

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Answer:

231  your welcome

Step-by-step explanation:

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