The speaker at the concert has the sound intensity level of 100 dB if we listen from the distance 5 m. How far from the speaker does the intensity level drop to the safe value of 85 dB?

Question

Physics

Sophie Chapman

27 May, 07:11

The speaker at the concert has the sound intensity level of 100 dB if we listen from the distance 5 m. How far from the speaker does the intensity level drop to the safe value of 85 dB?

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Answers (1)

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Harrison Sweeney · Answer 1

5.42 meters

Explanation:

Sound intensity varies inversely with the square of distance:

I = k / r²

When r = 5, I = 100.

100 = k / 5²

k = 2500

I = 2500 / r²

When I = 85:

85 = 2500 / r²

r = 5.42