Figure 12–32 shows various positions of a child on a swing moving toward a person on the ground who is blowing a whistle. At which position, A through E, will the child hear the highest frequency for the sound of the whistle? Explain your reasoning. Whiśtle Whistle, A В FIGURE 12-32 Question 17.

.  A bat sends of a sound wave 100 kHz and the sound waves travel through air at a speed of v=343m/s.�=343m/s. (a) If the maximum pressure difference is 1.30 Pa, what is a wave function that would model the sound wave, assuming the wave is sinusoidal? (Assume the phase shift is zero.) (b) What are the period and wavelength of the sound wave?

40. Go An ultrasonic ruler, such as the one discussed in Example 4 in Section 16.6, displays the distance between the ruler and an object, such as a wall. The ruler sends out a pulse of ultrasonic sound and measures the time it takes for the pulse to reflect from the object and return. The ruler uses this time, along with a preset value for the speed of sound in air, to determine the distance. Suppose that you use this ruler under water, rather than in air. The actual distance from the ultrasonic ruler to an ob- ject is 25.0 m. The adiabatic bulk modulus and density of seawater are B = 2.37 X 10° Pa and p = 1025 kg/m², respectively. Assume that the ruler uses a preset value of 343 m/s for the speed of sound in air. Determine the distance reading that the ruler displays.

Sound waves can be modeled as a spherical plane wave. For radial distances of 0.75 m, 2.5 m, and 5.5m, for a horn of 200 W, determine the inensities at each of these locations.

A rock band creates a sound intensity level of 111 dB at a distance of 20.0 m. (a) Calculate the sound intensity. W/m2 (b) Assuming sound from the amplifiers travels as a spherical wave, what average power do the amplifiers generate?

The toadfish makes use of resonance in a closed tube to produce very loud sounds. The tube is its swim bladder, used as an amplifier, the sound level of this reature has been measured as high as 75 dB. (a) Calculate the intensity of the sound wave emitted. W/m² (b) What is the intensity level if three of these fish try to imitate three frogs by saying "Budweiser" at the same time? dB