The sound pressure P for a given sound is given by:
P= 10 log W/ Wo
Its units are decibels (dB). W is the size of a variable energy source (called the sound power), measured in Watts. Wo is the lowest threshold of sound that humans can typically hear. It is a constant given by:
Wo=10^-12 W/m2
a) Find the rate of change of the sound pressure P with respect to time if W=7.2 and dW/dt = 0.5 at some given time t.
b) If the variable sound power W is given by W = t2 +t +1, find the rate of change of the sound pressure P, at time t = 3s.
c) If W = cos 0.2t, find the rate of change of the sound pressure P, at time t = 15 (calculators in radians)

Answers

Answer 1

Answer:

a. 0.302 dB/s

b. 2.34 dB/s

c. 1.24 dB/s

Step-by-step explanation:

a) Find the rate of change of the sound pressure P with respect to time if W=7.2 and dW/dt = 0.5 at some given time t.

Since P = 10log(W/W₀), its rate of change with respect to time is

dP/dt = dP/dW × dW/dt

dP/dW = d[10logW - 10logW₀]/dt

dP/dW = d[10lnW/2.303 - 10logW₀]/dt

= 10/2.303W - 0

= 10/(2.303W)

dP/dt = dP/dW × dW/dt

dP/dt = 10/(2.303W) × dW/dt

Since dW/dt = 0.5 when W = 7.2, then

dP/dt = 10/(2.303 × 7.2) × 0.5

dP/dt = 10/16.5816 × 0.5

dP/dt = 0.603 × 0.5

dP/dt = 0.302 dB/s

b) If the variable sound power W is given by W = t² + t + 1, find the rate of change of the sound pressure P, at time t = 3s.

Since P = 10log(W/W₀), its rate of change with respect to time is

dP/dt = dP/dW × dW/dt

dP/dW = d[10logW - 10logW₀]/dt

dP/dW = d[10lnW/2.303 - 10logW₀]/dt

= 10/2.303W - 0

= 10/(2.303W)

and dW/dt = d(t² + t + 1)/dt = 2t + 1

So, dP/dt = dP/dW × dW/dt

dP/dt = 10/(2.303W) × (2t + 1)

dP/dt = 10(2t + 1)/(2.303W)

dP/dt = 10(2t + 1)/[2.303(t² + t + 1)]

we then substitute t = 3 into the equation

dP/dt = 10(2t + 1)/[2.303(t² + t + 1)]

dP/dt = 10(2(3) + 1)/[2.303((3)² + 3 + 1)]

dP/dt = 10(6 + 1)/[2.303(9 + 3 + 1)]

dP/dt = 10(7)/[2.303(13)]

dP/dt = 70/29.939

dP/dt = 2.34 dB/s

c) If W = cos 0.2t, find the rate of change of the sound pressure P, at time t = 15 (calculators in radians)

Since dP/dt = dP/dW × dW/dt and dP/dW = 10/(2.303W) and W = cos(0.2t), dW/dt = -0.2sin(0.2t)

So, dP/dt = dP/dW × dW/dt

dP/dt = 10/(2.303W) × -0.2sin(0.2t)

dP/dt = -20sin(0.2t)/(2.303W)

dP/dt = -20sin(0.2t)/(2.303cos(0.2t))

dP/dt = -20tan(0.2t)/2.303

when t = 15, we have

dP/dt = -20tan(0.2 × 15)/2.303

dP/dt = -20tan3/2.303

dP/dt = -20 × -0.1425/2.303

dP/dt = 2.8509/2.303

dP/dt = 1.238

dP/dt ≅ 1.24 dB/s


Related Questions

The Acme Company manufactures widgets. The distribution of widget weights is bell-shaped. The widget weights have a mean of 42 ounces and a standard deviation of 10 ounces. Use the Empirical Rule.
a. 99.7% of the widget weights lie between _____ and _____.
b. What percentage of the widget weights lie between 26 and 66 ounces?
c. What percentage of the widget weights lie above 34?

Answers

Answer:

The answer is below

Step-by-step explanation:

The empirical rule states for a normal distribution, 68% of the data falls within one standard deviation, 95% falls within two standard deviations and 99.7% falls within three standard deviations.

z score is given by:

[tex]z=\frac{x-\mu}{\sigma}[/tex]

Given that mean (μ) = 42 ounces, standard deviation (σ) = 10 ounces.

a) 99.7% falls within three standard deviations. Therefore:

99.7% falls within μ ± 3σ = 42 ± 3(10) = 42 ± 30 = (12, 72)

Therefore 99.7% falls within 12 ounce and 72 ounce.

b) For x > 26

[tex]z=\frac{26-42}{10}=-1.6\\[/tex]

For x < 66

[tex]z=\frac{66-42}{10}=2.4\\[/tex]

From the normal distribution table, P(26 < x < 66) = P(-1.6 < z < 2.4) = P(z < 2.4) - P(z < -1.6) = 0.9918 - 0.0548 = 0.937 = 93.7%

c) For x > 34

[tex]z=\frac{34-42}{10}=-0.8\\[/tex]

From the normal distribution table, P(x > 34) = P(z > -0.8) = 1 - P(z < -0.8) = 1 - 0.2119 = 0.7881 = 78.81%

Answer:

Step-by-step explanation:

Given that:

Mean [tex]\mu[/tex] = 42

standard deviation [tex]\sigma[/tex] = 10

Using Empirical Rule:

[tex]\mu[/tex]  - [tex]\sigma[/tex] = 42 - 10 = 32                   [tex]\mu[/tex]  + [tex]\sigma[/tex] = 42 + 10 = 52                  

[tex]\mu[/tex]  - 2[tex]\sigma[/tex] = 42 - 2(10) = 22            [tex]\mu[/tex]  + 2[tex]\sigma[/tex] = 42 + 2(10) = 62         

[tex]\mu[/tex]  - 3[tex]\sigma[/tex] = 42 - 3(10) = 12             [tex]\mu[/tex]  + 3[tex]\sigma[/tex] = 42 + 3(10) = 72      

The curve is attached in the image below.

a). the widget of 99.7% lies between 12 and 72

b) 68 + 13.5 = 81.5%

c) 50 + 34 = 84%

Translate the phrase into an algebraic expression.
3 more than b

Answers

Answer:

b+3 or 3+b

Step-by-step explanation:

Find the zero of the polynomial 2y – 3​

Answers

Answer:

The zero of the polynomial is [tex]y = \frac{3}{2}[/tex]

Step-by-step explanation:

Zero of a polynomial:

The zeros of a polynomial are the values of the independent variable(in this case y) for which the polynomial is 0.

Polynomial 2y - 3

The zero is given by:

[tex]2y - 3 = 0[/tex]

[tex]2y = 3[/tex]

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

The zero of the polynomial is [tex]y = \frac{3}{2}[/tex]

A true false test contains 24 questions. In how many different ways can this test be completed. (Assume we
don't care about our scores.)

Answers

Answer:

The total number of ways to give the answer of the question is 16777216.

Step-by-step explanation:

Total number of questions = 24

The number of possibilities so that the answer is given is only 2. It is either true or false.

So, the total number of ways to complete the test is

[tex]2^{24} = 16777216[/tex]

This are diferente question help me please

Answers

Step-by-step

28.26 in84.9 m5024 cm277.45 mi 452.16 in1.36 mi44.15 m3.14 cm

I hope it helps you

15
Type the correct answer in each box. If necessary, round your answer(s) to the nearest hundredth.
The vertices of ABC are Al-2, 2), B6, 2), and 90, 8). The perimeter of ABC is
units, and its area is
square units.

Answers

9514 1404 393

Answer:

perimeter: 22.81 unitsarea: 24 square units

Step-by-step explanation:

The lengths of the sides can be found using the distance formula.

  d = √((x2 -x1)^2 +(y2 -y1)^2)

  AC = √((0 -(-2))^2 +(8 -2)^2) = √(4+36) = 2√10

  BC = √((0 -6)^2 +(8 -2)^2) = √(36+36) = 6√2

The distance AB is the difference of the x-coordinates of the points: 6-(-2) = 8.

Then the perimeter is ...

  P = a + b + c = 6√2 +2√10 +8 = 8.49 +6.32 +8 = 22.81 . . . units

__

The height of the triangle is the difference in y-values between vertex C and line AB: 8 -2 = 6. The area is given by the formula ...

  A = 1/2bh

  A = 1/2(8)(6) = 24 . . . square units

Suppose a certain state university's college of business obtained the following results on the salaries of a recent graduating class:

Finance Majors Business Analytics Majors
n1 = 140 n2 = 30
x1 = $48,237 x2 = $55,417
s1 = $19,000 s2 = $10,000

Required:
a. Formulate hypotheses so that, if the null hypothesis is rejected, we can conclude that salaries for Finance majors are significantly lower than the salaries of Business Analytics majors. Use α = 0.05. (Let μ1 = the population mean salary for Finance majors, and let μ2 = the population mean salary for Business Analytics majors.
b. What is the value of the test statistic?
c. What is the p-value? (Round your answer to four decimal places.)
d. What is your conclusion?

Answers

Answer:

Following are the responses to the given choice:

Step-by-step explanation:

For point a:

[tex]H_0: \mu_1 - \mu_2 = 0\\\\ H_1: \mu_1 - \mu_2 < 0[/tex]

For point b:

[tex]t = -2.953[/tex]

For point c:

[tex]\to p- value = 0.0021[/tex]

For point d:

Reject [tex]H_o[/tex]. It could deduce that the pay of higher banking is considerably lower than the pay of higher project management.

A restaurant charges large parties an amount that depends on the number of people
that are eating. The restaurant charges $650 for 25 people and $1,850 for 80 people.
What is the restaurant charging per person (unit rate)?

Answers

Answer:

$26 per person or $23.125 per person for the bigger group

Step-by-step explanation:


Which choice describes symmetry?
A. When something is exactly the same on one side as it is on the
other side.
B. When something looks completely different on one side than
the other side.
C. When something has a spherical shape.

Answers

Answer: A. When something is exactly the same on one side as it is on the

other side

Step-by-step explanation: symmetry mean symmetrical: aka they look the same :) hope this helped!

Kevin paid $2.52 for 6 juice boxes. How much should Kevin expect to pay for 18 juice boxes?

Answers

Answer:

7.56

Step-by-step explanation:

Kevin should expect to pay approximately $7.56 for 18 juice boxes based on the given information.

To find out how much Kevin should expect to pay for 18 juice boxes based on the given information, we can set up a proportion using the number of juice boxes and the cost:

In general, an expression refers to a combination of symbols, numbers, variables, and operators that represent a specific computation or value. Expressions are a fundamental concept in mathematics, programming, and logic.

Let "x" be the cost of 18 juice boxes.

We have the proportion:

6 juice boxes / $2.52 = 18 juice boxes / x

To solve for "x," we can cross-multiply:

6x = 18 x $2.52

6x = $45.36

Now, divide both sides by 6 to isolate "x":

x = $45.36 / 6

x ≈ $7.56

Therefore, According to the data provided, Kevin should budget about $7.56 for 18 juice cartons.

To know more about an expression follow

https://brainly.com/question/18650549

#SPJ2

The cost, in dollars, of a gym membership for n months can be described by the explicit equation Pn = 70 + 30n. What does this equation tell us?​

Answers

Answer:

30 plus 70 equals 100

Step-by-step explanation:

it tells the gum explicit equation

Evaluate the function at the given values of x. Round to 4 decimal places, if necessary. =fx7x

Answers

Step-by-step explanation:

what are the given values of x ?

there is nothing visible.

and what is the function itself ? f(x) = 7x ?

it is not clear.

x/4 - 3 = -7

what is x equal to?

Answers

Answer:

x=-16

Step-by-step explanation:

x/4-3=-7

x/4=-4

x=-16

What are the three plot points and is it over the x-axis or y-axis

Answers

Answer:

(-2,1), (0,1), and (2,0). its over the y axis

Step-by-step explanation:

Answer:

shift it 3 values right and 2 units up

Step-by-step explanation:

moving x-axis and moving y-axis

WILL MARK YOU JF YOU HELP PLEASE HELP ME!!

Answers

Answer : D) Perpendicular to a line through a point.

You can tell this is a construction for perpendicular to a line through a point because of the arcs created around one specific point, in this case it is point P.
The answer is D hope this helped !!

Which equation represents a line that passes through (5, 1) and has a slope of ?
O y-5 = {(x-1)
Oy- } = 5(x –1)
Oy-1 = {(x–5)
Oy - 1 = 5(x-)

Answers

Answer:

y - 1 = 5(x - 5)

Step-by-step explanation:

Given the following data;

Points (x, y) = (5, 1)

Slope = ?

From the question, the value of the slope is missing. Hence, let's assume a value of 5.

Mathematically, the equation of a straight line is given by the formula;

y = mx + c

Where;

m is the slope.

x and y are the points

c is the intercept.

To find the equation of line, we would use the following formula;

y - y1 = m(x - x1)

Substituting into the formula, we have;

y - 1 = 5(x - 5)

y - 1 = 5x - 25

y = 5x - 25 + 1

y = 5x - 24 = mx + c

evaluate g(x)=x/x-3, if g(1/2)

Answers

Answer:

-1/5

Step-by-step explanation:

g(x) = x/(x-3)

Substituting x = 1/2 in g(x),

g(1/2) = 1/2/(1/2-3)

= 1/2/(1/2-6/2)

= 1/2/(-5/2)

= 1/2 ÷ - 5/2

= 1/2 x -2/5

= - 1/5

Step-by-step explanation:

here is your answer

here is your answer

find the 6th term .
16,48,144​

Answers

Step-by-step explanation:

a=16

r=3

48/16=3

144/16=3

6th term

=ar^(n-1)

= 16(3)^(6-1)

=3888

Question 5
Refer to the data that you recorded in part D. In each row, compare the slope of ABto the slope of the perpendicular line. What is the
relationship between the two slopes? What conclusion can you draw about the relationship between the slopes of any two perpendicular lines?
Ok

Answers

Answer:

Step-by-step explanation:

Answer:

The product of the slopes of  and the line perpendicular to  through C is -1 in all cases. So, I can conclude that any two perpendicular lines have slopes that are negative reciprocals of each other.

Step-by-step explanation:

its correct

A parallelogram has base (2x - 1) metres and height (4x - 7) metres.
The area of the parallelogram is 1 m?.
(1) Show that 4x? - 9x + 3 = 0.
Answer (a)(i)
(*) Solve the equation 4x² – 9x + 3 = 0.
Show all your working and give your answers correct to 2 decimal places.

Answers

Answer:

0.4069 ; 1.843

Step-by-step explanation:

Given:

Base of parallelogram, b = (2x - 1)

Height = (4x - 7)

Area = 1

Area of parallelogram = Base * height

Area of parallelogram = (2x - 1) * (4x - 7)

(2x - 1) * (4x - 7) = 1

8x² - 14x - 4x + 7 = 1

8x² - 18x + 7 - 1 = 0

8x² - 18x + 6 = 0

Divide through by 2

4x² - 9x + 3 = 0

Solving the quadratic equation :

Using the formula

-b ± √(b² - 4ac) / 2a

a = 4 ; b = - 9 ; c = 3

Plugging in the values :

-(-9) ± √((-9)² - 4(4)(3)) / 2(4)

9 ± √(81 - 48) / 8

9 ± √33 / 8

(9 ± 5.7445626) / 8

(9 - 5.7445626) / 8) = 0.4069

(9 + 5.7445626) / 8 = 1.843

solve for x in the equation 9- x/4=2

Answers

Answer:

9-x/4=2

[tex] \frac{36 - x}{4} = 2[/tex]

[tex]36 - x = 2 \times 4[/tex]

[tex]36 - x = 8[/tex]

[tex] 36 - 8 = x[/tex]

[tex]28 = x[/tex]

[tex]x = 28[/tex]

9 - x/4 = 2

(36 - x)/4 = 2

36 - x = 8

36 - 8 = x

x = 28

I hope you understand...

Mark me as brainliest...

HI CAN SOMEONE THAT REALLY KNOWS ABOUT THIS HELP ME WITH FINAL EXAM...

The data represented by the following stem-and-leaf plot range from
to

489
5147
6235
769

A. 49; 79
B. 48; 79
C. 48; 76
D. 49; 76


Answers

Answer : B.) 48; 79

The minimum value is always at the start of the plot, and the maximum is always at the end.

What are the rational roots of f(d) = 5d - 6 + d-8?

Answers

5d - 6 + d - 8 = 0

6d - 14 = 0

6d = 14

d = 14/6

d = 2 and a third

Software Solution (SOS) helps subscribers solve software problems. All transactions are made over the telephone. For the year 2018, 10 engineers, most of whom are recent graduates, handled 119,000 calls. The average yearly salary for software engineers was $58,000. Starting in 2019, the firm retained and hired only software engineers with at least 2 years of experience. SOS raised the engineers’ salary to $73,000 per year. In 2019, eight engineers handled 127,000 calls.


Required:

1. Calculate the partial operational productivity ratio for both years.

2. Calculate the partial financial productivity ratio for both years. (Round your answers to 4 decimal places.)

Answers

Answer:

a. 11900, 15875

b. 0.2052, 0.2175

Step-by-step explanation:

number of engineers in 2018 = 10

calls handled in 2018 = 119000

average salary in 2018 = 58000

number of engineers in 2019 = 8

calls handled = 127000

salary = 73000

a.) operational productivity = output/input

in year 2018 = 119000/10= 11900

in year 2019 = 127000/8 = 15875

b.) ratio for both years = output/amount spent

in year 2018 = 119000/10*58000 = 0.2052

in year 2019 = 127000/8*73000 = 0.2175

The radius of a plant pot is 4.5 cm, and its height is 6 cm. What is the volume of the pot?
Use the value 3.14 for , and round your answer to the nearest whole number.
Be sure to include the correct unit in your answer.

Answers

Answer:

381 cm³

Step-by-step explanation:

Volume of the pot = volume of a cylinder

Volume of the pot = πr²h

Where,

π = 3.14

radius (r) = 4.5 cm

h = 6 cm

Substitute

Volume of the pot = 3.14*4.5²*6

Volume of the pot = 381.51 ≈ 381 cm³ (nearest whole number)

Which operation should you perform first in the expression 7x2^3?

Answers

Answer:

Below,

Step-by-step explanation:

The exponent part is done first

7 x 2^3

= 7 * 8

= 56.

You use the acronym PEMDAS:-

( E ( exponential) comes before  M (multiply))

anna opened a bank account she adds the same amount of money to it​

Answers

Answer:

What’s the numbers? Or the question?

Step-by-step explanation:

What’s the numbers or the question????

I need help with this.

Answers

9514 1404 393

Answer:

  $400

Step-by-step explanation:

The word "per" in math often means "divided by". To find price per square foot, find price divided by square feet.

  $700,000/(1750 ft²) = $400 /ft²

The price per square foot of House 4 was $400.

HELPPPPPPPPPP

Which of the following is equivalent to the expression below ?

square root 8 minus square root 72 plus square root 50 ?

A. 13 square root 2
B. 7 square root 2
C. 3 square root 2
D. Square root 2

Answers

Answer:

a13 square root

..cv

..

..

Simplify -4 + (-3) + 6.

Answers

Answer:3/6 in simplest fraction form is 1/2.

Step-by-step explanation:EASY and my chanel is FireFlameZero if u can check dat out

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