Discover the answers you need at Westonci.ca, where experts provide clear and concise information on various topics. Ask your questions and receive detailed answers from professionals with extensive experience in various fields. Join our Q&A platform to connect with experts dedicated to providing accurate answers to your questions in various fields.

The intensity, or loudness, of a sound can be measured in decibels (dB) according to the equation [tex]\( I(dB) = 10 \log \left(\frac{I}{I_0}\right) \)[/tex], where [tex]\( I \)[/tex] is the intensity of a given sound and [tex]\( I_0 \)[/tex] is the threshold of hearing intensity.

What is the intensity, in decibels, [tex]\( I(dB) \)[/tex], when [tex]\( I = 10^2 I_0 \)[/tex]?

A. 8
B. 9
C. 19
D. 80


Sagot :

To solve this problem, we'll use the formula for calculating the intensity of sound in decibels:

[tex]\[ I(dB) = 10 \log_{10}\left(\frac{I}{I_0}\right) \][/tex]

Given:
- [tex]\( I = 10^2 \cdot I_0 \)[/tex]
- [tex]\( I_0 \)[/tex] is the threshold of hearing intensity.

Step-by-step, we can substitute the given values into the formula:

1. Substitute [tex]\( I \)[/tex] with [tex]\( 10^2 \cdot I_0 \)[/tex]:

[tex]\[ I(dB) = 10 \log_{10}\left(\frac{10^2 \cdot I_0}{I_0}\right) \][/tex]

2. Simplify the fraction inside the logarithm:

[tex]\[ I(dB) = 10 \log_{10}(10^2) \][/tex]

3. Recognize that the [tex]\( I_0 \)[/tex] terms cancel each other out:

[tex]\[ I(dB) = 10 \log_{10}(10^2) \][/tex]

4. Apply the properties of logarithms. The logarithm of a power can be written as the exponent times the logarithm of the base:

[tex]\[ \log_{10}(10^2) = 2 \][/tex]

5. Multiply the result by 10:

[tex]\[ I(dB) = 10 \cdot 2 \][/tex]

6. Simplify the multiplication:

[tex]\[ I(dB) = 20 \][/tex]

Therefore, the intensity in decibels is [tex]\( 20 \, dB \)[/tex].