The intensity of sound decreases with distance according to the inverse square law. The formula for calculating sound intensity is:
I = P / (4πr²)
Where: I = Sound intensity P = Power emitted by the source r = Distance from the source
In this case, the power emitted by the source is 8 J/s, and the distance from the source changes from 5 m to 3 m.
For the first scenario, with a distance of 5 m: I1 = P / (4πr₁²) I1 = 8 J/s / (4π(5 m)²) I1 = 8 J/s / (4π(25) m²) I1 = 8 J/s / (100π) m² I1 ≈ 0.0255 J/(s·m²)
Now, for the second scenario, with a distance of 3 m: I2 = P / (4πr₂²) I2 = 8 J/s / (4π(3 m)²) I2 = 8 J/s / (4π(9) m²) I2 = 8 J/s / (36π) m² I2 ≈ 0.0707 J/(s·m²)
Therefore, when a person stands 3 m away from the sound source, the intensity of the sound is approximately 0.0707 J/(s·m²).