plz help me with this page ill give brainilest

Answer:

The decibel level of this second sound is 48.021 decibels.

Step-by-step explanation:

The acoustic intensity ([tex]B_{dB}[/tex]), measured in decibels, is defined by the following formula:

[tex]B_{dB} = 10\cdot \log_{10}\left(\frac{I}{I_{o}} \right)[/tex] (1)

Where:

[tex]I_{o}[/tex] - Reference sound intensity, measured in watts per square meter.

[tex]I[/tex] - Real sound intensity, measured in watts per square meter.

If we know that [tex]B_{dB} = 42\,dB[/tex] and [tex]I_{o} = 10^{-12}\,\frac{W}{m^{2}}[/tex], then the real sound intensity of the first sound is:

[tex]\frac{B_{dB}}{10} = \log_{10}\left(\frac{I}{I_{o}} \right)[/tex]

[tex]\frac{I}{I_{o}} = 10^{\frac{B_{dB}}{10} }[/tex]

[tex]I = I_{o}\cdot 10^{\frac{B_{dB}}{10} }[/tex]

[tex]I = \left(10^{-12}\,\frac{W}{m^{2}} \right)\cdot 10^{\frac{42\,dB}{10} }[/tex]

[tex]I = 1.585\times 10^{-8}\,\frac{W}{m^{2}}[/tex]

The real sound intensity of the second sound is four times greater, that is:

[tex]I' = 6.340\times 10^{-8}\,\frac{W}{m^{2}}[/tex]

If we know that [tex]I_{o} = 10^{-12}\,\frac{W}{m^{2}}[/tex] and [tex]I' = 6.340\times 10^{-8}\,\frac{W}{m^{2}}[/tex], then the acoustic intensity of the second sound is:

[tex]B_{dB} = 10\cdot \log_{10}\left(\frac{I'}{I_{o}} \right)[/tex]

[tex]B_{dB} = 10\cdot \log_{10}\left(\frac{6.340\times 10^{-8}\,\frac{W}{m^{2}} }{10^{-12}\,\frac{W}{m^{2}} } \right)[/tex]

[tex]B_{dB} = 48.021\,dB[/tex]

The decibel level of this second sound is 48.021 decibels.

Answer:

Step-by-step explanation:

Given function:

a) Maximum height is the vertex of the graph. Time needed:

If we double this time then diver will pass the peak point and it doesn't double the height

b) Maximum height is at vertex:

c) Distance from water after 2 seconds:

Answer:

x = 2

Step-by-step explanation:

7(3x + 5) - x = 75

1. Distributive property

multiply 7 by whatever is in the parenthesis

7*3x + 7*5 - x = 75

21x + 35 - x = 75

2. Combine like terms

21x - x = 20x

20x + 35 = 75

3. Subtract 35 on both sides

20x + 35 - 35 = 75 - 35

20x = 40

4. Divide both sides by 20 since u want to isolate the variable

20x/20 = 40/20

x = 2

And thats ur answer

Hope this helped!

Answer:

288

Step-by-step explanation:

First Divide 180/5=36. So then do 3 times 36=108. (108=People Singing, 180=People not singing). So add 108+180 to get 288.

The total number of people who attend the concert is 288.

Given that, for every 3 people at the concert singing along, there are 5 people not singing along.

The ratio is defined as the comparison of two quantities of the same units that indicates how much of one quantity is present in the other quantity.

Ratio of the number of people singing along at the concert to the number of people not singing along

= 3:5

Now, 3+5=8

The number of more people not singing along = 180

Let the total number of people be x

So, 5/8 × x=180

⇒ x=(180×8)/5

⇒ x=36×8

⇒ x=288

Therefore, the total number of people who attend the concert is 288.

To learn more about the ratio visit:

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Answer:

[tex]a=\sqrt{33}[/tex]

Step-by-step explanation:

When we solve for this we should always remember this formula [tex]a^2+b^2=c^2[/tex] and since we already know b and c we can plug that in to find out what a could be but we won't actually solve it.

[tex]a^2+b^2=c^2\\a^2+4^2=7^2\\a^2+16=49\\a^2=33\\\sqrt{a^2}=\sqrt{33}\\a=\sqrt{33}[/tex]

So a would equal whatever the square root of 33 is.

Answer:

24% yes yes yes

Answer:

24% or [tex]\frac{6}{25}[/tex]=24%

Step-by-step explanation:

We know that

[tex]\frac{6}{25}[/tex]

Is the same as

6÷25

Then, using long division gives us

0.24

Lastly, multiplying 0.24 by 100 gives us

24

Now add the percent sign

24%

Answer:

1200

Step-by-step explanation:

18/30 is the ratio of the girls compared to the class

you can simplify it to 3/5.

the equation to solve how many girls are in the school is 3/5= x/2000

cross multiply to get 5x=6000

x=1200

Answer:

5) we get a=6

6) we get c=8

Step-by-step explanation:

The triangles given are similar.

When the triangles are similar, the ratio of corresponding sides are also similar.

5) If c = 12, find a

We will use the ratio

[tex]\frac{30}{12}=\frac{15}{a}[/tex]

Now cross multiply to find value of a

[tex]30*a=12*15\\a=\frac{180}{30}\\a=6\\[/tex]

So, we get a=6

6. If b = 6.4, find c

We will use the ratio

[tex]\frac{30}{c}=\frac{24}{6.4}[/tex]

Now cross multiply to find value of b

[tex]30*6.4=24*c\\c=\frac{192}{24}\\c=8\\[/tex]

So, we get c=8

Answer:

there are different intrest rates, depending on where it is. but im choosing 8400

Step-by-step explanation:

Answer:

X/12

Step-by-step explanation:

X - whole drywall

X/4 -quarters

X/4/3=X/12 fraction of a whole sheet is each of these small pieces

Answer:

38 yards

Step-by-step explanation:

All you have to do is add up all that yardsgained and subtract the yards lost:

32-7+15-2=38

Answer:

38

Step-by-step explanation:

32-7=25

25+15=40

40-2=38

Answer:1 black 4 white

Step-by-step explanation:

It must be 2:3 so you have to change the current ratio from black to white(7:8) to 2:3

So the first number has to be the closets multiple of 2(8) and you have to divide 8 by 2 to get 4 and multiply that by 3 to get the ratio 8:12 which is equivalent to 2:3

Answer:

21:84

Step-by-step explanation:

Answer:

Step-by-step explanation:

We have a box with 84 chocolates

63 are dark, milk=84-63=21

21/63=1/3 is the ratio

for each 1 milk chocolate we have 3 dark chocolates

The value of x is 20.

There are three commonly used trigonometric identities.

Sin x = Perpendicular / Hypotenuse

Cosec = Hypotenuse / Perpendicular

Cos x = Base / Hypotenuse

Sec x = Hypotenuse / Base

Tan x = Perpendicular / Base

Cot x = Base / Perpendicular

We have,

Sin 30 = 10 / x ______(10

We know that,

Sin 30 = 1/2 _____(2)

So,

Substituting (2) in (1).

1/2 = 10/x

x = 10 x 2

x = 20

Thus,

The value of x is 20.

Learn more about trigonometric identities here:

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Answer:

have a good day too

Step-by-step explanation:

Answer:

h(x) = [tex](x+5)^{2}[/tex] -18

Step-by-step explanation:

-b/2a is the formula to find the vertex's x coordinate.

-10/2(1) = -5 and "(x+5)" represents a translation to the left 5 units, so that must be the answer

Answer:

60

Step-by-step explanation:

The answer of this question is 60 degree

Answer:

x>-1

Step-by-step explanation:

Answer:

gave no examples.. this is what I got

Step-by-step explanation:

Answer:

11.7

Step-by-step explanation:

Answer:

What about the wink face?

Step-by-step explanation:

Answer:

x = 4

Step-by-step explanation:

The inner and outer triangles are similar, thus the ratios of corresponding sides are equal, that is

[tex]\frac{x}{5}[/tex] = [tex]\frac{8}{10}[/tex] ( cross- multiply )

10x = 40 ( divide both sides by 10 )

x = 4

Answer:

x = 43000/9 or 4777.7 (i'm not 100% sure on this, so i apologize if i'm incorrect)

Step-by-step explanation:

The equation you were given was:

amount of solution • rate of concentration = amount of pure acid

By looking at the question, you can conclude that the amount of solution being used is 18%. You need to turn that into a decimal, therefore it'd be 0.18.

You can also conclude that the amount of pure acid being used is 860 milliliters. So, from this, you're able to fill in 2 parts of the equation:

0.18 • x = 860 mL

Now, all there's left to do is solve for x! To do this ,you'll need to rearrange the multiplication problem into a division problem.

860 / 0.18 = x

x = 43000/9 or 4777.7

Answer: 8x−3

Step-by-step explanation:

Let's simplify step-by-step.

7−x−−5x−10+4x

=7+−x+5x+−10+4x

Combine Like Terms:

=7+−x+5x+−10+4x

=(−x+5x+4x)+(7+−10)

=8x+−3

If I Helped, Please Mark Me As Brainliest, Have A Great Day :D

Answer:

8 x -3

Step-by-step explanation:

because you do the equation on math w a y

Answer:

I think it´s 12

Step-by-step explanation:

Answer:

12

Step-by-step explanation:

because 15% (or 0.15) times 80 equals 12.

Answer:

b

Step-by-step explanation:

Answer:

the answer would be A

Step-by-step explanation:

Answer:

A. 1,876 tissue holders

Step-by-step explanation:

Answer:

A translation is a transformation that occurs when a figure is moved from one location to another location without changing its size, shape or orientation. In the coordinate plane we can draw the translation if we know the direction and how far the figure should be moved.

Step-by-step explanation:

Answer:

A translation is converting another language into English

Step-by-step explanation:

Answer:

wouldnt it be d

Step-by-step explanation:

Answer:

x = 1

Step-by-step explanation: