The area of a circle is increasing at a rate of 0.4 cm square per second. What is the rate of change of the circumference of the circle when its radius is 5cm?

Answers

Answer 1

Answer: 4π cm^2/minute

Step-by-step explanation:

Rate of change :

Change with respect to time (dr/dt)

dr/dt = 0.4cm^2/s

r = 5cm

The rate of change when the Radius is 5cm

Area / Circumference of a circle (A) = πr^2

From chain rule of differentiation:

dA/dt = (dr/dt) * (dA/dr)

If A = πr^2

dA/dr = 2πr

dA/dr = 2π * 5 = 10π

However,

dA/dt = (dr/dt) * (dA/dr)

dA/dt = (0.4) * (10π)

dA/dt = 4π cm^2/minute


Related Questions

1) In rectangle ABCD, AE is perpendicular on diagonal BD, BE=3DE and AC∩BD={O}.
1. DE/EO=?
2. If BD=8√2 inches, find out the lenght of AE
3. Calculate the measure of angle AOD.

2) In rectangle MNPQ, MA⊥NQ, A∈NQ, MA∩PQ={B}. If AN measures 12 inches, AQ=27 inches, calculate the lenght of MA and MB.

Please help me with these. Or at least with one of them.

Answers

Answer:

to be honest I'm not sure how to do

A sixth-grade class is growing plants for their
science projects. Each student spent $1.00 for a
package of seeds and $2.50 for a container to
plant the seeds in. There are 30 students in the
class. How much money did the sixth-grade class
spend on seeds and containers in all?

Answers

Answer:

5.76

Step-by-step explanation:

Answer:

$105

Step-by-step explanation:

Each student buys one package of seeds and one container

s = Amount of students; p = price of seed package; c = price of container

s*(p+c)=30(1.00+2.50)=30(3.5)$105.

Hope This Helps!

Shelley and David have a sweet tooth. Shelley spent \$2.65 for 15 sour keys and 2 chocolate bars. David bought 3 chocolate bars and 10 sour keys for \$3.35 at the same store. Find the cost of each chocolate bar and each sour key at this store. If you need 8 chocolate bars and 24 sour keys to give to friends coming to your birthday party, how much will they cost you at this store?

Answers

Answer:

Chocolate bars: $0.95 each

Sour keys: $0.05 each

Total cost for 8 chocolate bars and 24 sour keys: $8.80

Step-by-step explanation:

sour keys=x

chocolate bars=y

15x+2y=2.65

10x+3y=3.35

multiply the second equation by 1.5

15x+4.5y=5.025

2.5y=2.375

y=0.95

Chocolate bars are $0.95 each.

Now substitute the y value in one of the equations

15x+2(0.95)=2.65

15x+1.9=2.65

15x=0.75

x=0.05

Sour keys are $0.05 each.

For the second part of the question, just multiply the number of chocolate bars by the cost and same thing with the sour keys and add them.

Final answer: $8.80

Banita has a piece of string that is One-tenth times 7 inches long. Which fraction is equal to the length of Banita’s string?

Answers

Answer: The length is 7/10 inches.

Step-by-step explanation:

So if is says that the string is  1/10 times 7 inches long, then it represents the length of the string.

So  L = [tex]\frac{1}{10}*7[/tex]  

     L = 7/10

Answer:

l=7/10

Step-by-step explanation:

Compute the value of each expression 7−17

Answers

Answer: -10

Step-by-step explanation:

7 - 17 = -10.  An easy way to do this (with only two terms) is to just flip it, and do 17 - 7 = 10, then make 10 negative(-10)

Hope it helps <3

A company offering online speed reading courses claims that students who take their courses show a 5 times (500%) increase in the number of words they can read in a minute without losing comprehension. A random sample of 100 students yielded an average increase of 415% with a standard deviation of 220%. Calculate a 95% confidence interval for the average increase in number of words students can read in a minute without losing comprehension. Choose the closest answer.

Answers

Answer:

C.I = (371.88  , 458.12)

Step-by-step explanation:

Given that:

sample size n = 100

sample mean [tex]\overline x =[/tex] 415

standard deviation = 220

The objective is to calculate the  95% confidence interval for the average increase in number of words students who can read in a minute without losing comprehension.

At 95% confidence interval; level of significance ∝ = 1 - 0.95

level of significance ∝ = 0.05

[tex]z_{\alpha/2} = 0.05/2[/tex]

[tex]z_{\alpha/2} = 0.025[/tex]

The critical value at [tex]z_{\alpha/2} = 0.025[/tex] is 1.96

C.I = [tex]\overline x \pm M.O,E[/tex]

C.I = [tex]\overline x \pm z_{\alpha/2} \dfrac{\sigma }{\sqrt{n}}[/tex]

C.I = [tex]415\pm 1.96 \dfrac{220 }{\sqrt{100}}[/tex]

C.I = [tex]415\pm 1.96 *\dfrac{220 }{10}[/tex]

C.I = [tex]415\pm 1.96 *22[/tex]

C.I = [tex]415\pm 43.12[/tex]

C.I = (371.88  , 458.12)

the legnth of rectangular sheet decreases by 34.5 cm its width decreases proportionally that is by the same percentage. if the sheets original width was half of the legnth and the new (smaller) area was 1.2 m^2 what was original sheet's width

Answers

Answer:

The original width was 94.71 cm

Step-by-step explanation:

Given:

new smaller area = 1.2m^2

Decrease in length of the rectangular sheet = 34.5cm

Therefore:

1. the final width of the sheet is given as

2X^2 = 1.2 m^2

X^2 - 0.6 m^2

X^2 = 10000 * 0.6 cm

X = 77.46 cm (this is the width)

2. The length of the sheet

= 2 * 77.46

= 154.92 cm.

3. Initial length of the sheet

= 154.92 + 34.5

= 189.42 cm.

4. Initial width of the sheet ( original ).

= 189.42 / 2

= 94.71 cm.

5. Initial area of the sheet

= 94.71 * 189.92

= 17939.9 cm^2

New area of the sheet

= 79.46 * 154.92

= 12000.1 cm^2

Difference between the initial and new area

= 17939.9 - 12000.1

= 5939.86 cm^2

Percentage of area decrease

= 5939.86 ' 17939.9

= 33.1%

Please help don't understand at all​

Answers

(i) Note that it is given to you that 3a + 2b = 9

You are trying to find the value of 9a + 6b. Find what is multiplied to both the variable a & b. Divide:

(9a + 6b)/(3a + 2b) = 3

Next, multiply 3 to the 9 on the other side of the equation:

3 x 9 = 27

27 is the value of 9a + 6b.

(ii) Note that it is given to you that 8x + 6y = 60

You are trying to find the value of 4x + 3y. Find what is multiplied to both the variable x & y. Divide:

(8x + 6y)/(4x + 3y) = 2

Next, divide 2 from the 60 on the other side of the equation:

60/2 = 30

30 is the value of 4x + 3y.

~

Answer:

(i) 27, (ii) 30

Step-by-step explanation:

i. since 9a + 6b is 3 times 3a + 2b then the and is 3 times 9 = 27

ii. since 4x + 3y is half of 8x + 6y then 60 /2 = 30

The roots of 100x2 – 20x + 1 = 0 is:​

Answers

Answer:

             x = 0.1    

Step-by-step explanation:

[tex]100x^2-20x+1=0\\\\(10x)^2-2\cdot10x\cdot1+1^2=0\\\\(10x-1)^2=0\\\\10x-1=0\\\\10x=1\\\\x=0.1[/tex]

Una compañía sabe que si produce "x" unidades mensuales su utilidad "u" se podría calcular con la expresión: u(x)=-0.04x^2+44x-4000 donde "u" se expresa en dólares. Determine la razón del cambio promedio de la utilidad cuando el nivel de producción cambia de 600 a 620 unidades mensuales. Recuerde que la pendiente de la recta secante a la gráfica de la función representa a la razón de cambio promedio.

Answers

Answer:

The ratio of the average change in profit when the level of production changes from 600 to 620 units per month is -24 : 5.

Step-by-step explanation:

The question is:

A company knows that if it produces "x" monthly units its utility "u" could be calculated with the expression: u (x) = - 0.04x ^ 2 + 44x-4000 where "u" is expressed in dollars. Determine the ratio of the average change in profit when the level of production changes from 600 to 620 units per month. Remember that the slope of the secant line to the graph of the function represents the average rate of change.

Solution:

The expression for the utility is:

[tex]u (x) = - 0.04x ^ {2} + 44x-4000[/tex]

It is provided that the slope of the secant line to the graph of the function represents the average rate of change.

Then the ratio of the average change in profit when the level of production changes is:

[tex]\text{Average change in profit}=\frac{u(x_{2})-u(x_{1})}{x_{2}-x_{1}}[/tex]

Compute the values of u (x₁) and u (x₂) as follows:

x₁ = 600

[tex]u (x_{1}) = - 0.04x_{1} ^ {2} + 44x_{1}-4000[/tex]

         [tex]= - 0.04(600) ^ {2} + 44(600)-4000\\=-14400+26400-4000\\=8000[/tex]

x₂ = 620

[tex]u (x_{2}) = - 0.04x_{2} ^ {2} + 44x_{2}-4000[/tex]

         [tex]= - 0.04(620) ^ {2} + 44(620)-4000\\=-15376+27280-4000\\=7904[/tex]

Compute the average rate of change as follows:

[tex]\text{Average change in profit}=\frac{u(x_{2})-u(x_{1})}{x_{2}-x_{1}}[/tex]

                                      [tex]=\frac{7904-800}{620-600}\\\\=\frac{-96}{20}\\\\=-\frac{24}{5}\\\\=-24:5[/tex]

Thus, the ratio of the average change in profit when the level of production changes from 600 to 620 units per month is -24 : 5.

Help! Pls pls pls! Fast!

Answers

it is transformed [tex]|x|[/tex] function. moved down by and right by 1 unit,

so $y=|x-1|-1$

sinxcosy=1/2(sin(x+y)+cos(x-y))
True or False?

Thanks for the help!

Answers

Answer:

False

Step-by-step explanation:

To be able to answer this, we will need to make a reference to the sum and product formula.

What we have in the question is the product and we want to see if the sum correlates.

Using the sum formula, we have the value on the right hand side as;

(1/2)[sin(x+y)+sin(x-y)]

Seeing that the expression we have here is not equal to that which was given, we can conclude that the answer is false

You have $1000 to invest in an account and need to have $2000 in one year. What interest rate would you need to have in order to have this if the amount is compounded weekly? Round your answer to the nearest percent.

Answers

Answer:

[tex]\large \boxed{\sf \ \ 70\% \ \ }[/tex]

Step-by-step explanation:

Hello,

We assume that the year is 52 weeks, and we note r the interest rate we are looking for. The rate is expressed in percent and is annually, meaning that the investment is, after the first week :

   [tex]1000\cdot (1+\dfrac{r\%}{52})=1000\cdot (1+\dfrac{r}{5200})[/tex]

For the second week

   [tex]1000\cdot (1+\dfrac{r}{5200})^2[/tex]

After 52 weeks

   [tex]1000\cdot (1+\dfrac{r}{5200})^{52}[/tex]

and we want to be equal to 2000 so we need to solve:

[tex]1000\cdot (1+\dfrac{r}{5200})^{52}=2000\\\\\text{*** divide by 1000 both sides ***}\\\\(1+\dfrac{r}{5200})^{52}=\dfrac{2000}{1000}=2\\\\\text{*** take the ln **}\\\\52\cdot ln(1+\dfrac{r}{5200})=ln(2)\\\\\text{*** divide by 52 ***}\\\\ln(1+\dfrac{r}{5200})=\dfrac{ln(2)}{52}\\\\\text{*** take the exp ***}\\\\\displaystyle 1+\dfrac{r}{5200}=exp(\dfrac{ln(2)}{52})=2^{(\dfrac{1}{52})}=\sqrt[52]{2}\\\\r = 5200\cdot (\sqrt[52]{2}-1)=69.77875...[/tex]

Rounded to the nearest percent, the solution is 70%.

If you want to double your capital in one year with weekly compounding you need an interest rate of 70% !!

Hope this helps.

Do not hesitate if you need further explanation.

Thank you

Answer:

4%

Step-by-step explanation:

help again plz.......​

Answers

The answer is B I think

Point A is at (-6,6) and point C is at (-6,-2). Find the coordinates of point B on Ac such that AB =3/4AC​

Answers

Answer:

  B(-6, 0)

Step-by-step explanation:

You want to find B such that ...

  (B -A) = (3/4)(C -A) . . . . the required distance relation

  4(B -A) = 3(C -A) . . . . . . multiply by 4

  4B = 3C +A . . . . . . . . . . add 4A, simplify

Now, we can solve for B and substitute the given coordinates:

  B = (3C +A)/4 = (3(-6, -2) +(-6, 6))/4 = (-24, 0)/4 = (-6, 0)

The coordinates of point B are (-6, 0).

Answer:

the answer your looking for is (-3,-3)

Step-by-step explanation:

A rectangular solid has edges whose lengths are in the ratio 1:2:3. If the volume of the solid is 864 cubic units, what are the lengths of the solid's edges?

Answers

Answer: 5.24 units, 10.48 units , 15.72  units

Step-by-step explanation:

Volume of a rectangular solid is given by :-

V = lwh, where l = length , w= width and h = height

Given: A rectangular solid has edges whose lengths are in the ratio 1:2:3.

Let lengths of the rectangular solid x , 2 x, 3x.

volume of the solid is 864 cubic units

Then, Volume of rectangle = [tex]x (2x)(3x) =864\ \text{cubic units}[/tex]

[tex]\Rightarrow\ 6x^3 = 864\\\\\Rightarrow\ x^3 =144\\\\\Rightarrow\ x=(144)^{\frac{-1}{3}}\approx5.24[/tex]

Lengths of rectangular solid 5.24 units, 2 (5.24) units , 3(5.24) units

= 5.24 units, 10.48 units , 15.72  units

10. Read the following word problem, then choose which linear equation models the problem.

The length of a rectangle is six feet more than twice the width. The rectangle’s perimeter is 84 feet. Find the width and length of the rectangle.
A. 2w + 6 + w = 84
B. 2(2w + 6) + 2w = 84
C. 2(2w +6) • (2w) = 84
D. (2w + 6) • (w) = 84

Answers

Answer:

D. ( 2w+6). (w)

i tried my best

hope this is the answer

stay at home stay safe

i will give brainliest.The product of 5 and the sum of 12 and a certain number is 10. What is the number​

Answers

Answer: x=-10

Step-by-step explanation:

5*(12+x)=10

Distribute

60+5x=10

Subtract(60)

5x=-50

x=-10

Hope it helps <3

Answer:

Heeyyy hope it helps

Step-by-step explanation:

Ok, so the product is the answer to a multiplication problem.

The product of 5 and the sum of a number(X) and 3 is

5(X + 3) = 12

5X + 15 = 12

5X = 12 - 15

5X = -3

X = -3/5

if you apply the changes below to the quadratic parent function f(x)=x^2.which of these in the equation of the new function? shift 1 unit right ,vertically stretch by a factor of 3,reflects over x-axis

Answers

Answer:

Transformed   [tex]\,\,f(x)= -3\,(x-1)^2[/tex]

Step-by-step explanation:

The process of shifting the graph of the function 1 unite to the right can be obtained by subtracting 1 to the x-coordinate in the expression of the function:

[tex]f(x)=x^2\\new\,f(x) =(x-1)^2[/tex]

The process of stretching vertically the function, would be accomplished by multiplying now the full function by "3":

[tex]new \,\,f(x)= 3\,(x-1)^2[/tex]

the reflection over the x-axis is obtained by multiplying the full function by the constant "-1":

[tex]new \,\,f(x)= -3\,(x-1)^2[/tex]

Find the measure of b.
Please help

Answers

Answer:

125 degrees

Step-by-step explanation:

Using a theorem, you know that angle a is half of 110. Also, in all quadrilaterals   inscribed in a circle, the opposite angles are supplimentary. So then, knowing that angle a is 55 degrees, you can come to the conclusion that b is 125 degrees.

Hope this is helpful! :)

The graphed line shown below is y=-3x+6...Which equation, when graphed with the given equation, will form a system that has no solution?​

Answers

Answer:

The equation, when graphed together with the line y=-3x +6, which will form a system of equations with no solution is y=-3(x +6), meaning the second option on the picture.

Step-by-step explanation:

hope this helps!

Answer: 2 or B

Step-by-step explanation:

Please help me, im in desperate need of help for these questions

Answers

Answer:

For the first one, answer is dilation of 2

Step-by-step explanation:

you see the coordinates for triangle A'B'C' are all doubled the coordinates of triangle ABC

Please answer it now in two minutes

Answers

Answer:3.2 ft

Step-by-step explanation:

sin 32°=[tex]\frac{yz}{6}[/tex]

cross multiply

sin 32° x 6=yz

0.5299 x 6 =yz

yz=3.1795

≅3.2ft

Which is a diagonal through the interior of the cube? Side A H Side B E Side C H Side F G

Answers

Answer:

Option (A)

Step-by-step explanation:

Every cube has 8 vertices and 6 faces.

Cube shown in the picture attached,

Diagonal through interior of the given cube will be the segments joining the vertices A-H, G-B, C-F and D-E.

Therefore, from the given options diagonal of the interior of the cube will be Side AH.

Option A will be the answer.

Answer:

the awnser is A

Step-by-step explanation:

i took a quiz

A bag contains two red marbles, two green ones, one lavender one, five yellows, and six orange marbles. HINT [See Example 7.] How many sets of four marbles include one of each color other than lavender?

Answers

Answer: 120

Step-by-step explanation:

Given: A bag contains two red marbles, two green ones, one lavender one, five yellows, and six orange marbles.

The total number of marbles in the bag : 2+2+1+5+6=16

Now, the number of ways of selecting sets of four marbles include one of each color other than lavender is

[tex]\( C(2,1) \times C(2,1) \times C(5,1) \times C(6,1)=2 \times 2 \times 5 \times 6\)=120[/tex]  [[tex]\because\ C(n,1)=n[/tex]]

Hence, the number of sets of four marbles include one of each color other than lavender = 120

Urgent help I need it right now!!!!

Answers

Answer:

[tex]\boxed{\sf 30 \ bean \ cans}[/tex]

Step-by-step explanation:

The ratio of bean cans to corn cans is 6 : 7

Given that Corn cans = 35

Let the bean can be x

So,

The proportion for it will be:

6 : 7 = x : 35

Product of Means = Product of Extremes

7 * x = 6 * 35

7x = 210

Dividing both sides by 7

x = 30

So, 30 bean cans have to be put on the table to hold the needed ratio

write the sum of twice a number and eleven as an algebraic expression

Answers

Answer:

2x-11

Step-by-step explanation:

2 x X = 2x + 11

what is the lengthy of side s of the square below

Answers

Answer:

D. 4√2

Step-by-step explanation:

A triangle with 45°, 45°, and 90° is a special right triangle.

hypotenuse = √2 · leg

1. Set up the equation

8 = √2 · x

2. Divide by √2 and solve

x = [tex]\frac{8}{\sqrt{2} }[/tex] · [tex]\frac{\sqrt{2} }{\sqrt{2}}[/tex] = [tex]\frac{8\sqrt{2} }{2}[/tex] = 4√2

In rectangle ABCD the diagonals intersect each other at point O and m∠ABD=30°. Find BC if AC = 16 in....

Answers

Answer:

BC = 8

Step-by-step explanation:

16 ( sin 30 degrees ) = BC

16 (0.5)

16/2

BC = 8

Give the other person brainliest they deserve it.

A newspaper article claimed: "The average cost of weekly groceries is $124.50." What
statistical measurement are they most likely claiming?
O A. median
B. mean
C. range
D. mode

Answers

i think it’s the Mean
because the meaning of mean is an average of multiple sums being divided ;)

The average cost of weekly groceries is $124.50."  The statistical measurement are they most likely claiming is Mean

The correct option is (B)

what is Mean?

The arithmetic mean of a given data is the sum of all observations divided by the number of observations.

For example, a cricketer's scores in five ODI matches are as follows: 12, 34, 45, 50, 24. To find his average score in a match, we calculate the arithmetic mean of data using the mean formula:

Mean = Sum of all observations/Number of observations

Median

The value of the middlemost observation, obtained after arranging the data in ascending or descending order, is called the median of the data.

For example, consider the data: 4, 4, 6, 3, 2. Let's arrange this data in ascending order: 2, 3, 4, 4, 6. There are 5 observations. Thus, median = middle value i.e. 4.

Mode

The value which appears most often in the given data i.e. the observation with the highest frequency is called a mode of data.

As per the situation we have given average cost of groceries.

The mean is also the average sum of data divided by total number of data.

Hence, The statistical measurement is Mean.

Learn more about mean here:

https://brainly.com/question/15323584

#SPJ2

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