Academic Integrity: tutoring, explanations, and feedback — we don’t complete graded work or submit on a student’s behalf.

table 15.3 in the textbook gives an estimate for the sound intensity of a whispe

ID: 2001445 • Letter: T

Question

table 15.3 in the textbook gives an estimate for the sound intensity of a whisper at 1.0 m to be 1.0x10^-11 W/m^2. What is the sound intensity of a whisper at a distance of 3.5 m, in W/m^2? What is the corresponding sound intensity level in dB? table 15.3 in the textbook gives an estimate for the sound intensity of a whisper at 1.0 m to be 1.0x10^-11 W/m^2. What is the sound intensity of a whisper at a distance of 3.5 m, in W/m^2? What is the corresponding sound intensity level in dB? table 15.3 in the textbook gives an estimate for the sound intensity of a whisper at 1.0 m to be 1.0x10^-11 W/m^2. What is the sound intensity of a whisper at a distance of 3.5 m, in W/m^2? What is the corresponding sound intensity level in dB? table 15.3 in the textbook gives an estimate for the sound intensity of a whisper at 1.0 m to be 1.0x10^-11 W/m^2. What is the sound intensity of a whisper at a distance of 3.5 m, in W/m^2? What is the corresponding sound intensity level in dB?

Explanation / Answer

Now the inverse square law is applied; the intensity of a sound varies inversely with the square of the distance from the source of the sound.

I = k • (1/R2)

Since distance is increasing by a factor 3.5 so intensity will be reduced by a factor 3.52

Hence sound intensity at 3.5 m=1*10-11/3.52=8.163*10-13W/m2

Corresponding sound level in dB can be calculated using

dB = 10 * log( I / 1.0 x 10-12 W/m2)

=-0.88dB