In: Physics
The sound intensity is 0.0072 W/m2 at a distance of 20 m from an isotropic point source of sound. (a) What is the power of the source? (b) What is the sound intensity 6.1 m from the source? (c) What is the sound level 20 m from the source?
Initial distance from the source of sound = R1 = 20 m
Sound intensity at a distance of 20 m from the source = I1 = 0.0072 W/m2
Sound level 20 m from the source = 1
1 = 98.57 dB
Power of the source = P
P = I1(4R12)
P = 4I1R12
P = 4(0.0072)(20)2
P = 36.19 W
Sound intensity at a distance of 6.1 m from the source = I2
New distance from the source = R2 = 6.1 m
P = I2(4R22)
P = 4I2R22
36.19 = 4I2(6.1)2
I2 = 0.0774 W/m2
a) Power of the source = 36.19 W
b) Sound intensity 6.1 m from the source = 0.0774 W/m2
c) Sound level 20 m from the source = 98.57 dB