Problem 4.181

Find the damping coefficient $\gamma$ of a sound wave if at distances $r_{1}=10 \mathrm{~m}$ and $r_{2}=20 \mathrm{~m}$ from a point isotropic source of sound the sound wave intensity values differ by a factor $\eta=4.5$ .

\gamma=\frac{\ln \left(\eta r_{1}^{2} / r_{2}^{2}\right)}{2\left(r_{2}-r_{1}\right)}=6 \cdot 10^{-3} \mathrm{~m}^{-1}

Elastic Waves. Acoustics.