Expensive amplifier A is rated at 280 W, while the more modest amplifier B is rated at 45 W. What output wattage amp would sound about twice as loud as the 45-W amp?

A guitar string produces 3 beat/s when sounded with a 350-Hz tuning fork and 8 beat/s when sounded with a 355-Hz tuning fork. What is the vibrational frequency of the string? Explain your reasoning.

A source emits sound of wavelengths 2.54 m and 2.72 m in air. How many beats per second will be heard? (Assume T = 20°C.)

You look directly overhead and see a plane exactly 1.45 km above the ground flying faster than the speed of sound. By the time you hear the sonic boom, the plane has traveled a horizontal distance of 2.0 km. See Fig. 16–40. Determine (a) the angle of the shock cone, θ, and (b) the speed of the plane and its Mach number. Assume the speed of sound is 330 m/s.

Assuming that the maximum displacement of the air molecules in a sound wave is about the same as that of the speaker cone that produces the sound (Fig. 16–46), estimate by how much a loudspeaker cone moves for a fairly loud (105 dB) sound of 35 Hz.