With which of the following does the growth rate decrease as the population gets bigger?

To understand the decibel scale. The decibel scale is a logarithmic scale for measuring the sound intensity level. Because the d

frez [133]

The question is incomplete. Here is the complete question.

To understand the decibel scale. The decibel scale is a logarithmic scale for measuring the sound intensity level. Because the decibel scale is logarithmic, it changes by an additive constant when the intensity when the intensity as measured in W/m² changes by a multiplicative factor. The number of decibels increase by 10 for a factor of 10 increase in intensity. The general formula for the sound intensity level, in decibels, corresponding to intensity I is

$\beta=10log(\frac{I}{I_{0}} )dB$ ,

where $I_{0}$ is a reference intensity. for sound waves, $I_{0}$ is taken to be $10^{-12} W/m^{2}$ . Note that log refers to the logarithm to the base 10.

Part A: What is the sound intensity level β, in decibels, of a sound wave whose intensity is 10 times the reference intensity, i.e. $I=10I_{0}$ ? Express the sound intensity numerically to the nearest integer.

Part B: What is the sound intensity level β, in decibels, of a sound wave whose intensity is 100 times the reference intensity, i.e. $I=100I_{0}$ ? Express the sound intensity numerically to the nearest integer.

Part C: Calculate the change in decibels ( $\Delta \beta_{2},\Delta \beta_{4}$ and $\Delta \beta_{8}$ ) corresponding to f = 2, f = 4 and f = 8. Give your answer, separated by commas, to the nearest integer -- this will give an accuracy of 20%, which is good enough for sound.

Answer and Explanation: Using the formula for sound intensity level:

A) $I=10I_{0}$

$\beta=10log(\frac{10I_{0}}{I_{0}} )$

$\beta=10log(10 )$

β = 10

The sound Intensity level with intensity 10x is 10dB.

B) $I=100I_{0}$

$\beta=10log(\frac{100I_{0}}{I_{0}} )$

$\beta=10log(100)$

β = 20

With intensity 100x, level is 20dB.

C) To calculate the change, take the f to be the factor of increase:

For $\Delta \beta_{2}$ :

$I=2I_{0}$

$\beta=10log(\frac{2I_{0}}{I_{0}} )$

$\beta=10log(2)$

β = 3

For $\Delta \beta_{4}$ :

$I=4I_{0}$

$\beta=10log(\frac{4I_{0}}{I_{0}} )$

$\beta=10log(4)$

β = 6

For $\Delta \beta_{8}$ :

$I=8I_{0}$

$\beta=10log(\frac{8I_{0}}{I_{0}} )$

β = 9

Change is

$\Delta \beta_{2},\Delta \beta_{4}$ , $\Delta \beta_{8}$ = 3,6,9 dB

6 0

3 years ago

What is the rate at which an object changes position

zaharov [31]

It is the velocity of the object.

4 0

3 years ago

Which of the following are disadvantages of solar energy? Check all that apply. A. It contributes to global warming. B. It is ex

guajiro [1.7K]

B, C, and D.

Solar energy is green energy, it wouldn't contribute to global warming. However some places of the world don't receive as much sunlight (the poles) and at night you don't receive as much sunlight either. Solar energy is also very expensive to farm.

8 0

3 years ago

Two cars, a Porsche Boxster convertible and a Toyota Scion xB, are traveling at constant speeds in the same direction. Suppose,

fenix001 [56]

Answer:

It will take 29.31 seconds for the Boxster to catch the Scion

Explanation:

Given the data in the question;

lets say Toyota Scion xB is car A and Porsche Boxster convertible is B and Toyota Scion xB is car A

the distance travelled by car A is

x = $V_{A}$ × t

where $V_{A}$ is the speed of the car and t is time

the distance travelled by car B before reaching car A will be;

x + x₀ = $V_{B}$ × t

Now lets replace x by $V_{A}$ × t

so

( $V_{A}$ × t) + x₀ = $V_{B}$ × t

x₀ = ( $V_{B}$ × t) - ( $V_{A}$ × t)

x₀ = t ( $V_{B}$ - $V_{A}$ )

t = x₀ / ( $V_{B}$ - $V_{A}$ )

so we substitute

t = 170 m / (24.4 - 18.6)

t = 170 / 5.8

t = 29.31 s

Therefore; it will take 29.31 s for the Boxster to catch the Scion

8 0

3 years ago

Times will the kinetic one

mixer [17]

Answer:

The new kinetic energy is 9 times of the initial kinetic energy.

Explanation:

The kinetic energy of an object is given by the formula as follows :

$E=\dfrac{1}{2}mv^2$

Where

m is mass and v is speed of the body

If the speed of the body is tripled. Let v' is the new speed, v' = 3v. The new kinetic energy is E' and it is given by :

$E'=\dfrac{1}{2}mv'^2\\\\\text{Put v' = 3v}\\\\E'=\dfrac{1}{2}m\times (3v)^2\\\\=\dfrac{1}{2}m\times 9v^2\\\\=9\times (\dfrac{1}{2}mv^2)\\\\E'=9\times E$

Hence, the new kinetic energy is 9 times of the initial kinetic energy.

3 0

3 years ago