A sound source emits acoustic waves uniformly in all directions at a constant power. If an observer triples their distance from the source, by how many decibels does the sound intensity level decrease? (Take )
Answer and explanation
Correct answer: A. Approximately 9,54 dB
- Step 1: Inverse square law: . Step 2. Decibel change: . Step 3. dB. Answer: Approximately 9,54 dB. Why not the others: Intensity drops by factor of 9, producing a 9,54 dB reduction.
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