Physical World
A point source emits sound waves isotropically. The intensity of the waves 2.50 m from the source is $$1.91 \times 10^{-4} W/m^{2}$$. Assuming that the energy of the waves is conserved , find the power of the source.
A loudspeaker at a rock concert generates $$10^{-2}\ W/m^2$$ at $$20\ m$$ at a frequency of $$1\ kHz$$. Assume that the speaker spreads its energy uniformly in all directions.What is the total acoustic power output of the speaker?
Given:-
Intensity at 20 m = $$10^{-2} W/m^2$$
Frequency = $$1KHz$$
$$(a)P= 4 \pi r^2 I= 4 \pi \times 400 ×10^{-2}W = 50.3 W$$.
A point source emits sound waves isotropically. The intensity of the waves 2.50 m from the source is $$1.91 \times 10^{-4} W/m^{2}$$. Assuming that the energy of the waves is conserved , find the power of the source.
Two atmospheric sound sources A and B emit isotropically at constant power. The sound levels $$\beta$$ of their emissions are plotted in Fig. 17-40 versus the radial distance $$r$$ from the sources. The vertical axis scale is set by $$\beta_1 = 85.0 \space dB$$ and $$\beta_2 = 65.0 \space dB$$. What are (a) the ratio of the larger power to the smaller and (b) the sound level difference at $$r = 10 \space m$$?
The sound intensity is $$ 0.0080 \mathrm{W} / \mathrm{m}^{2} $$ at a distance of $$ 10 \mathrm{m} $$ from an isotropic point source of sound. What is the power of the source?