How to solve this ??

Complete question is;

A 10 cm thick grindstone is initially 200 cm in diameter, and it is wearing away at a rate of 50 cm/hr. At what rate is its diameter decreasing?

Answer:

Diameter is decreasing at the rate of 5/(2πr) cm/hr

Step-by-step explanation:

We are told the stone is wearing away at a rate of 50 cm/hr. This means the volume is decreasing. Thus;

dV/dt = -50 cm/hr

Now, a grindstone is in the shape of a cylinder. Thus, volume of grindstone is;

V = πr²h

dV/dr = 2πrh

Now,to find the rate at which the diameter is decreasing, we'll write;

dr/dt = (dV/dt)/(dV/dr)

dr/dt = -50/(2πrh)

We are given;

Diameter = 200 cm

Radius; r = 200/2 = 100 cm

Thickness; h = 10 cm

Thus;

dr/dt = -50/(2π × r × 10)

dr/dt = -5/(2πr) cm/hr

The rate at which grindstone diameter decreases is [tex]-5/2\pi r \;{\rm cm/hr}[/tex] and this can be determined by using the given data.

Given :

A 10 cm thick grindstone is initially 200 cm in diameter and it is wearing away at a rate of 50 [tex]\rm cm^3/hr[/tex].

The following steps can be used in order to determine the rate at which grindstone diameter decreases:

Step 1 - According to the given data, the rate at which grindstone volume decreases is:

[tex]\dfrac{dV}{dt} = 50\;{\rm cm^3/hr}[/tex]        --- (1)

Step 2 -  The formula of the volume of the cylinder (grindstone) is given below:

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

Step 3 - Differentiate the above expression with respect to 'r'.

[tex]\dfrac{dV}{dr} = 2\pi r h[/tex]          --- (2)

Step 4 - So, using the expression (1) and (2) the rate at which grindstone diameter decreases is:

[tex]\dfrac{dr}{dt}=\dfrac{\frac{dV}{dt}}{\frac{dV}{dr}}[/tex]

[tex]\dfrac{dr}{dt}=\dfrac{-50}{2\pi r \times 10}\\[/tex]

[tex]\dfrac{dr}{dt} = -\dfrac{5}{2\pi r }\; {\rm cm/hr}[/tex]

So, the rate at which grindstone diameter decreases is [tex]-5/2\pi r \;{\rm cm/hr}[/tex].

For more information, refer to the link given below:

https://brainly.com/question/12748872

Answer:

33.

Step-by-step explanation:

I assume that the 2 triangles are similar.

x/77 = 24/56

56x = 77*24

x = (77*24(/56

x = 33.

Answer:

Step-by-step explanation:

First find the angle in the lower left.

180 - 100 = 80

3x + 2x + 80 = 360

solve for x

5x = 280

5x/5 = 280/ 5

x = 56

Plug this in to make sure the equation is true

3(56) + 2(56) + 80 = 360

168 + 112 + 80 = 360

360 =360

Therefore x = 56

Answer:

perimeter =2(l+w)

6.6=2(l + 1.8)

6.6= 2L + 3.6

L=3/2 =1.5

ans =1.5

9514 1404 393

Answer:

  4) y = -3(x+2)^2 +4; y = -3x^2-12x-8; ABC=(-3, -12, -8)

  5) y = 0.5(x-1)^2-2; y = 0.5x^2-x-1.5; (h,k) = (1, -2)

  6) y = -0.3(x+2)^2-6; y = -0.3x^2-1.2x-7.2; (h,k) = (-2, -6)

Step-by-step explanation:

Writing a quadratic equation through a set of points is most easily done using the regression function of a graphing calculator or spreadsheet.

4) see the first attachment

  y = -3(x+2)^2 +4 . . . vertex form

  y = -3x^2 -12x -8 . . . standard form (A, B, C) = (-3, -12, -8)

__

5) see the second attachment

  y = 0.5(x -1)^2 -2 . . . vertex form; vertex = (1, -2)

  y = 0.5x^2 -x -1.5 . . . standard form

__

6) see the third attachment

  y = -0.3(x +2)^2 -6 . . . vertex form; vertex = (-2, -6)

  y = -0.3x^2 -1.2x -7.2 . . . standard form

_____

Doing this without machine help requires you pick a form of the equation you want, fill in the x- and y-values for three of the given points, then solve the resulting equations for the unknown parameters. Usually, we use the form ...

  y = ax^2 +bx +c

which will result in three linear equations for a, b, c. Those can be solved by any of the usual methods.

Answer:

1

Step-by-step explanation:

3/4 + 1/4 since they both have a 4 as the denominator you only have to add the top since they made it easy. and since that would be 4/4 your answer would be 1 whole.

im not sure just yet

Answer:  d = -9/8

Steps: 5d + ½ = d - 4

Subtract ½ from both sides: 5d + ½ - ½  = d - 4 - ½

Simplify: 5d = d - 9/2

Subtract d from both sides: 5d - d = d - 9/2 - d

Simplify: 4d = -9/2 ÷ 4

Simplify: d = -9/8

PLz mark brainliest:)

Answer:

Step-by-step explanation:

The Order of Operations is very important when simplifying expressions and equations. The Order of Operations is a standard that defines the order in which you should simplify different operations such as addition, subtraction, multiplication and division.

This standard is critical to simplifying and solving different algebra problems. Without it, two different people may interpret an equation or expression in different ways and come up with different answers. The Order of Operations is shown below.

Parentheses and Brackets -- Simplify the inside of parentheses and brackets before you deal with the exponent (if any) of the set of parentheses or remove the parentheses.

Exponents -- Simplify the exponent of a number or of a set of parentheses before you multiply, divide, add, or subtract it.

Multiplication and Division -- Simplify multiplication and division in the order that they appear from left to right.

Addition and Subtraction -- Simplify addition and subtraction in the order that they appear from left to right.

Before we begin simplifying problems using the Order of Operations, let's examine how failure to use the Order of Operations can result in a wrong answer to a problem.

Without the Order of Operations one might decide to simplify the problem working left to right. He or she would add two and five to get seven, then multiply seven by x to get a final answer of 7x. Another person might decide to make the problem a little easier by multiplying first. He or she would have first multiplied 5 by x to get 5x and then found that you can't add 2 and 5x so his or her final answer would be 2 + 5x. Without a standard like the Order of Operations, a problem can be interpreted many different ways

We cannot combine the variable terms before using the distributive property when solving the equation as it will results in wrong answer.

What is distributive property of multiplication over addition ?

If we multiply a number by the sum of more than two, we use the distributive property of multiplication over addition.

Here the expression given is :

7(x+5)-x=42

The Order of Operations is very important when simplifying expressions and equations. The Order of Operations is a standard that defines the order in which you should simplify different operations such as addition, subtraction, multiplication and division.

Parentheses and Brackets -- Simplify the inside of parentheses and brackets before you deal with the exponent (if any) of the set of parentheses or remove the parentheses.

Exponents -- Simplify the exponent of a number or of a set of parentheses before you multiply, divide, add, or subtract it.

Multiplication and Division -- Simplify multiplication and division in the order that they appear from left to right.

Addition and Subtraction -- Simplify addition and subtraction in the order that they appear from left to right.

Without the Order of Operations one might decide to simplify the problem working left to right. He or she would add two and five to get seven, then multiply seven by x to get a final answer of 7x. Another person might decide to make the problem a little easier by multiplying first. He or she would have first multiplied 5 by x to get 5x and then found that you can't add 2 and 5x so his or her final answer would be 2 + 5x. Without a standard like the Order of Operations, a problem can be interpreted many different ways.

Read more about property of multiplication here :

https://brainly.com/question/14391436

#SPJ2

Answer:

answer is 9 in th by form of the good answer is the to k=9.0 10á gd gd

Answer:

Not a Function

Step-by-step explanation:

Answer:

-3 = -12

Step-by-step explanation:

Have a great day

I hope that is the answer you are looking for :)

Answer:

There are four main types of transformations: translation, rotation, reflection and dilation.Translation moves the object without rotating it or changing its size. Reflection flips the object about a line of reflection. Rotation rotates a figure about a fixed point. Dilation changes the size of a figure without changing its essential shape.When you reflect a point across the x-axis, the x-coordinate remains the same,but the y-coordinate is transformed into its opposite. a negative angle of rotation turns the figure in a clockwise direction.Transformation can be done in a number of ways, including reflection, rotation, and translation. ~When you reflect a point across the x-axis, the x-coordinate remains the same,but the y-coordinate is transformed into its opposite. a negative angle of rotation turns the figure in a clockwise direction.

Step-by-step explanation:

Transformation simply means changing the size and location of shapes, lines and points in the coordinate geometry

The similarities

Translations, reflections, and rotations are all rigid transformations

This means that, they do not change the side lengths and angle measure of the shape they transform.

The differences

Translation: can only change the position of shapes without rotating or flipping the shape.

Rotation: This means that a shape is to be turned around a center at a particular degree

Reflection: This simply means that, a shape is mirrored over a line

Real-world transformation

A scenario is when the blades of a fan rotates when the fan is powered on

Examples

Reflection

Rotation

Translation

Read more about transformations at:

https://brainly.com/question/13801312

Answer:x= -3/8

Step-by-step explanation:

Answer:

-3/8

Step-by-step explanation:

4(3-2x)=15

-3/8

Answer:

v=2(x - 1)(x-6)=2(x²-6x-x+6)=12x²-12x-2x+12

v = 12x²-14x+12  standard form

Step-by-step explanation:

Answer:

Step-by-step explanation:

75

We're given two pairs of congruent sides, and a pair of congruent angles. The angles are not between the two congruent sides. So we don't have enough information to know if the triangles are congruent or not. SSA is not a valid congruence theorem. This is because there are some cases where two triangles are possible leading to ambiguity.

If the marked angles were between the tickmarked sides, then we could use SAS.

9514 1404 393

Answer:

  -2

Step-by-step explanation:

The average rate of change on the interval [3, 9] is ...

  (f(9) -f(3))/(9 -3) = (41 -53)/(9 -3) = -12/6 = -2

Given :-

ΔBCD ≅ ΔGEF

Then :-

∠B <=> ∠G ( ∠B = ∠G )

∠C <=> ∠E ( ∠C = ∠E )

∠D <=> ∠F ( ∠ D = ∠F )

BC <=> GE ( BC = GE )

CD <=> EF ( CD = EF )

BD <=> GF ( BD = GF )

Using this let us find CD .

CD = EF

Which means :-

[tex] 3x + 8 = 4x + 6[/tex]

[tex]8 = 4x + 6 - 3x[/tex]

[tex]8 = 1x + 6[/tex]

[tex]1x + 6= 8[/tex]

[tex]1x = 8 - 6[/tex]

[tex]1x = 2[/tex]

[tex]x = 2[/tex]

Then :-

EF =

[tex]EF = 4x + 6 \\ = 4 \times 2 + 6 \\ = 8 + 6 \\ = 14[/tex]

CD =

[tex]CD = 3x + 8 \\ = 3 \times 2 + 8 \\ = 6 + 8 \\ = 14[/tex]

△BCD≅△GEF

The measure of CD is 14

Given :

Two triangles are congruent

△BCD≅△GEF

When triangles are congruent then the sides are equal

[tex]BC=GE\\CD=EF\\DB=FG\\[/tex]

Given that CD=3x+8 and EF=4x+6

[tex]CD=EF\\3x+8=4x+6\\3x+8-3x=4x-3x+6\\8=x+6\\8-6=x+6-6\\x=2[/tex]

The value of x=2

Now we find measure of CD

[tex]CD=3x+8\\CD=3(2)+8\\CD=14[/tex]

The measure of CD is 14

Learn more :  brainly.com/question/18373823

Answer:

-44ax^2-198x^2+66a+297

Step-by-step explanation:

there

Answer:

There's no evidence to show that the recent experience suggests a decline in spending.

Step-by-step explanation:

We are given;

Population mean; μ = $2.5

Population Standard deviation; σ = $0.9

Sample mean; x¯ = $2.1

Sample size; n = 18

Significance level; α = 0.01

Let's define the hypothesis;

Null hypothesis; H0: μ ≥ $2.5

Alternative hypothesis; Ha: μ < $2.5

z-score formula is;

z = (x¯ - μ)/(σ/√n)

z = (2.1 - 2.5)/(0.9/√18)

z = -0.4/0.2121

z = -1.886

Using the p-value from z-score calculator attached and using z = -1.886; α = 0.01; one tail; we have;

P-value = 0.2965

This is more than the significance level. Thus, we will fail to reject the null hypothesis and conclude that there is no evidence to show that the recent experience suggests a decline in spending.

Answer:

[tex] y = \frac{2}{3}x - 6 [/tex]

Step-by-step explanation:

Recall that the the equation of a line in slope-intercept form is given as [tex] y = mx + b [/tex].

m = the slope of the line

b = the y-intercept. This is the point at which the line intercepts the y-axis.

We are given:

slope (m) = ⅖

y-intercept (b) = -6

All you need to do to get an equation of the line is to simply substitute m = ⅔ and b = -6 into [tex] y = mx + b [/tex].

[tex] y = \frac{2}{3}x + (-6) [/tex]

[tex] y = \frac{2}{3}x - 6 [/tex]

The equation for the line is .[tex] y = \frac{2}{3}x - 6 [/tex]

Answer:

The null hypothesis                 [tex]H_o : \mu = 3.2 \ mg/dl[/tex]

The alternative hypothesis      [tex]H_a : \mu > 3.2 \ mg/dl[/tex]

Step-by-step explanation:

From the question we are told that

  The mean is  [tex]\mu = 3.2 \ mg/dl[/tex]

   The standard deviation is [tex]\sigma = 1.5 mg/dl[/tex]

   The sample size is  n = 25

    The sample mean is  [tex]\= x = 3.75 \ mg /dl[/tex]

Generally

   The null hypothesis is : That the mean of the  Arsenic blood concentrations in healthy individuals is [tex]\mu = 3.2 \ mg/dl[/tex]

i.e

The null hypothesis  [tex]H_o : \mu = 3.2 \ mg/dl[/tex]

    The alternative hypothesis is : That the mean of the  Arsenic blood concentrations in healthy individuals is greater than  [tex]\mu = 3.2 \ mg/dl[/tex]

The alternative hypothesis      [tex]H_a : \mu > 3.2 \ mg/dl[/tex]

Answer:

-4w+4

Step-by-step explanation:

Answer:

-4w+4 Is te correct answer

Answer:

A. 20%

Step-by-step explanation:

fruit punch A is half of fruit punch B so times 35 by 2 and then subtract 50. 50 came from 25 times 2.

Answer:

5/9

Step-by-step explanation:

2/3 • 5/2 • 2/3

1/3 • 2/5 • 2/3

multiply 1/3 for 5/2

5

-----------

3 • 2

multiply 3 for 2

5/6 • 2/3

anular el factor común 2

5/3 • 1/3

multiply 5/3 for 1/3

5

------------

3 • 3

multiply 3 for 3

5/9

the result

5/9

form decimal

0.5

Answer:

Answer is 12x+4. Hope that helped.

Answer:

134 is the answer

Answer: 134

Step-by-step explanation:

54+ (48+72) x 2/3

54+120x2/3=134