Get personalized answers to your unique questions on IDNLearn.com. Our experts provide timely and accurate responses to help you navigate any topic or issue with confidence.

The loudest sound measured one night during a hockey game was 112 dB. The loudest sound measured during a hockey game the next night was 118 dB. What fraction of the sound intensity of the second game was the sound intensity of the first game?

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

Where:
[tex]\[ L \][/tex] = loudness in decibels
[tex]\[ I \][/tex] = sound intensity in watts per square meter [tex]\(\left(\frac{\text{watts}}{m^2}\right)\)[/tex]
[tex]\[ I_0 = 10^{-12} \text{ watts per square meter} \left(\frac{\text{watts}}{m^2}\right) \][/tex]

A. 0.25
B. 0.78
C. 0.95
D. 0.99


Sagot :

Sure, let's solve this problem step by step.

1. Understand the given data:

- The loudness levels [tex]\( L_1 \)[/tex] and [tex]\( L_2 \)[/tex] for the two hockey games are 112 dB and 118 dB, respectively.
- The reference intensity [tex]\( I_0 = 10^{-12} \)[/tex] watts/m[tex]\(^2\)[/tex].

2. Convert loudness levels back to intensity:

The formula to relate loudness (in decibels) to intensity is:
[tex]\[ L = 10 \log_{10} \left( \frac{I}{I_0} \right) \][/tex]
Rearranging this formula to solve for [tex]\( I \)[/tex], we get:
[tex]\[ I = I_0 \cdot 10^{\frac{L}{10}} \][/tex]

Now we will use this formula to find the intensities [tex]\( I_1 \)[/tex] and [tex]\( I_2 \)[/tex].

- For the first game ([tex]\( L_1 = 112 \)[/tex] dB):
[tex]\[ I_1 = I_0 \cdot 10^{\frac{112}{10}} = 10^{-12} \cdot 10^{11.2} = 10^{-12 + 11.2} = 10^{-0.8} \][/tex]
This simplifies to:
[tex]\[ I_1 \approx 0.1584893192461111 \text{ watts/m}^2 \][/tex]

- For the second game ([tex]\( L_2 = 118 \)[/tex] dB):
[tex]\[ I_2 = I_0 \cdot 10^{\frac{118}{10}} = 10^{-12} \cdot 10^{11.8} = 10^{-12 + 11.8} = 10^{-0.2} \][/tex]
This simplifies to:
[tex]\[ I_2 \approx 0.6309573444801944 \text{ watts/m}^2 \][/tex]

3. Compute the fraction of the sound intensity of the first game to the second game:

The fraction of the intensities is given by:
[tex]\[ \text{Fraction} = \frac{I_1}{I_2} \][/tex]

Substituting the values of [tex]\( I_1 \)[/tex] and [tex]\( I_2 \)[/tex]:
[tex]\[ \text{Fraction} = \frac{0.1584893192461111}{0.6309573444801944} \approx 0.2511886431509572 \][/tex]

4. Conclusion:

The fraction of the sound intensity of the first game to the sound intensity of the second game is approximately [tex]\( 0.2512 \)[/tex], or 0.25 when rounded to two decimal places.

Therefore, the correct answer is:
[tex]\[ \boxed{0.25} \][/tex]