## Essential University Physics: Volume 1 (4th Edition) Clone

We know the following equation for the sound intensity level: $\beta = 10log (\frac{I}{I_0})$ This can be simplified to: $I = I_010^{.1\beta}$ $I = \frac{10^{.1\beta}}{10^{12}}$ $I =10^{.1\beta-12}$ We know the following equation for the power of a spherical wave: $I = \frac{P}{4\pi r^2}$ Thus, we should plot I versus $\frac{1}{4\pi r^2}$, where r is the distance in the table. We now plot these points in excel. Doing this, we find that the trendline, when the y-intercept is set equal to zero, has a slope of 1489.1, which is our value for power.