1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
jek_recluse [69]
3 years ago
8

The radius of a circular puddle is growing at a rate of 20 cm/sec. (a) how fast is its area growing at the instant when the radi

us is 40 centimeters? hint [see example 1.] (round your answer to the nearest integer.) incorrect: your answer is incorrect. cm2/s (b) how fast is the area growing at the instant when it equals 64 square centimeters? hint [use the area formula to determine the radius at that instant.] (round your answer to the nearest integer.)
Mathematics
1 answer:
Readme [11.4K]3 years ago
5 0
Part (a)
 
The expression for the circle area is given by:
 A = pi * r ^ 2
 Where,
 r: radio
 We now derive the expression of the area with respect to time:
 A '= 2 * pi * r * r'
 Substituting values:
 A '= 2 * pi * (40) * (20)
 A '= 5026.6 cm ^ 2 / s
 Answer:
 its area is growing at the instant when the radius is 40 centimeters at:
 A '= 5026.6 cm ^ 2 / s<span>
 Part b)
 A = pi * r ^ 2
 We look for the radio:
 r = root (A / pi)
 r = root (64 / pi)
 r = 4.5 cm
 We now derive the expression of the area with respect to time:
 A '= 2 * pi * r * r'
 Substituting values:
 A '= 2 * pi * (4.5) * (20)
 A '= 565.5 cm ^ 2 / s
 Answer:
 its area is growing at:
 A '= 565.5 cm ^ 2 / s</span>
You might be interested in
Please help with all three will give brainliest and $5
Dafna1 [17]

\frac{x}{y}Answer:

Six would be your answer

Step-by-step explanation:

2y-9= y-2

-y        -Y

y-9=-2

y=-2+9

y=6

7 0
3 years ago
Please PLEASE HELP me
Phantasy [73]
It has to be the first one
6 0
3 years ago
Read 2 more answers
The playing time X of jazz CDs has the normal distribution with mean 52 and standard deviation 7; N(52, 7).
natita [175]

Answer:

68% of jazz CDs play between 45 and 59 minutes.

Step-by-step explanation:

<u>The correct question is:</u> The playing time X of jazz CDs has the normal distribution with mean 52 and standard deviation 7; N(52, 7).

According to the 68-95-99.7 rule, what percentage of jazz CDs play between 45 and 59 minutes?

Let X = <u>playing time of jazz CDs</u>

SO, X ~ Normal(\mu=52, \sigma^{2} =7)

The z-score probability distribution for the normal distribution is given by;

                                    Z  =  \frac{X-\mu}{\sigma}  ~ N(0,1)

Now, according to the 68-95-99.7 rule, it is stated that;

  • 68% of the data values lie within one standard deviation points from the mean.
  • 95% of the data values lie within two standard deviation points from the mean.
  • 99.7% of the data values lie within three standard deviation points from the mean.

Here, we have to find the percentage of jazz CDs play between 45 and 59 minutes;

   For 45 minutes, z-score is =  \frac{45-52}{7}  = -1

   For 59 minutes, z-score is =  \frac{59-52}{7}  = 1

This means that our data values lie within 1 standard deviation points, so it is stated that 68% of jazz CDs play between 45 and 59 minutes.

6 0
3 years ago
The picture is the answer​
kari74 [83]

Answer:

4. 3

The answer is the last option, all you do is reduce

Step-by-step explanation:

rise over run = rise/run = 6/2

reduce,

6/2

3/1

3x

6 0
3 years ago
Michelle bought a gift priced at $5.00.she gave the store clerk $20.00.she received three bills as change.what bills did she rec
goblinko [34]
The answer would be $5 bills

5*4 = 20 and he spent 5 you would only have 3 $5 bills.
5 0
3 years ago
Read 2 more answers
Other questions:
  • In a department store the owner paid $15 for 1kg of sugar.The owner marked the price up by 10% for the customers.How much dose h
    9·1 answer
  • To you divide fractions, you have to ______ by the reciprocal
    9·2 answers
  • I need help me please now
    9·2 answers
  • Write the equation of the line in slope-intercept form.
    9·1 answer
  • the number 1 through 10 are written on individual cards and placed in a bag. if you reach into the bag and pull out a card, what
    14·1 answer
  • GIVING 20 POINTS What is the product?
    8·2 answers
  • In this polygon Find x
    5·1 answer
  • Bella surveyed the first 15 students in the lunch line.
    7·1 answer
  • What is the inverse of the function f(x) = 2x - 10?
    6·1 answer
  • Solve the proportion for x
    8·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!