The intensity of sound is measured on the decibel scale, [tex]dB[/tex]. The equation [tex]dB = 10 \log I[/tex] represents the decibel level, where [tex]I[/tex] is the ratio of the sound to the human hearing threshold.

On a construction site, a large sheet of steel is dropped on the ground. The noise it makes is 100,000 times greater than the human hearing threshold. To the nearest whole number, what is the decibel value of the noise?



Answer :

To find the decibel (dB) value of the noise on the construction site, we will use the formula:

[tex]\[ dB = 10 \log I \][/tex]

where [tex]\( I \)[/tex] is the intensity ratio of the noise to the human hearing threshold. In this case, the noise is 100,000 times greater than the human hearing threshold. Thus, [tex]\( I = 100,000 \)[/tex].

Let's go through the steps to calculate the decibel value:

1. Identify the intensity ratio [tex]\( I \)[/tex]:

Given, [tex]\( I = 100,000 \)[/tex].

2. Apply the decibel formula:

Substitute [tex]\( I \)[/tex] into the formula [tex]\( dB = 10 \log I \)[/tex]:
[tex]\[ dB = 10 \log 100,000 \][/tex]

3. Calculate the logarithm:

To find the logarithm of 100,000, recognize that 100,000 can be written as [tex]\( 10^5 \)[/tex]:
[tex]\[ \log 100,000 = \log (10^5) \][/tex]

Using the property of logarithms [tex]\(\log (10^b) = b \log 10\)[/tex], and knowing that [tex]\(\log 10\)[/tex] is 1:
[tex]\[ \log (10^5) = 5 \log 10 = 5 \][/tex]

Thus,
[tex]\[ \log 100,000 = 5 \][/tex]

4. Substitute the logarithm value back into the decibel formula:

[tex]\[ dB = 10 \times 5 = 50 \][/tex]

5. Round the result, if needed:

Since the result is already a whole number, there is no need to round further.

Therefore, the decibel value of the noise is [tex]\( 50 \)[/tex].