A source emits a sound in the shape of a cone, as shown in the figure below. If you measure the intensity to be 100 W/m² at a distance of 0.5 m, what is the power of the source?

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

(b) 35 Hz. <IMAGE>

(I) What are the lowest and highest frequencies that an ear can detect when the sound level is 40 dB? (See Fig. 16–6.)

(II) Expensive amplifier A is rated at 280 W, while the more modest amplifier B is rated at 45 W.

(b) What output wattage amp would sound about twice as loud as the 45-W amp?

(II) Your ears can accommodate a huge range of sound levels. What is the ratio of highest to lowest intensity at (a) 100 Hz, (b) 5000 Hz? (See Fig. 16–6.)

A source emits sound spherically with a power of 2.2 × 10⁴ W. What is the minimum distance away from this sound that would be considered safe (a volume of 150 dB or less)?

A sound wave from a police siren has an intensity of 0.01 W/m² at a certain distance. A second sound wave from an ambulance has a sound intensity level 8 dB greater than the police siren, when measured at the same distance. What is the sound intensity level (in dB) of the sound wave due to the ambulance?