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Figure 17-32 shows the output from a pressure monitor mounted at a point along the path taken by a sound wave of a single frequency traveling at 343 m/s through air with a uniform density of 1.21 kg/m3. The vertical axis scale is set by ▵ps = 4.0 mPa. If the displacement function of the wave is s(x, t) = sm cos(kx − ωt), what are (a) sm, (b) k, and (c) ω? The air is then cooled so that its density is 1.35 kg/m3 and the speed of a sound wave through it is 320 m/s. The sound source again emits the sound wave at the same frequency and same pressure amplitude. What now are (d) sm, (e) k, and (f) ω?
Figure 17-32 Problem 14.
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