Workers around jet aircraft typically wear protective devices over their ears. Assume that the sound level of a jet airplane engine, at a distance of 30 m, is 130 dB, and that the average human ear has an effective radius of 2.0 cm. What would be the power intercepted by an unprotected ear at a distanceof 30 m from a jet airplane engine?

An 6 hour exposure to a sound intensity level of 95.0 dB may cause hearing damage. What energy in joules falls on a 0.900 cm diameter eardrum so exposed?

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?

An 6 hour exposure to a sound intensity level of 95.0 dB may cause hearing damage. What energy in joules falls on a 0.600 cm diameter eardrum so exposed?

Suppose that a public-address system emits a 494 Hz sound uniformly in all directions. (a) If the air temperature is 250C (sound travels at 346 m/s), what is the wavelength of this sound? (b) If the intensity at a location 22 m away from the sound source is 3x10-4 W/m2, what is the power of the sound coming from the speaker?

A weather emergency siren is mounted on a tower, 153 m above the ground. On one hand, it would be a good idea to make the siren very loud so that it will warn as many people as possible. On the other hand, safety regulations prohibit the siren from exceeding an intensity level of 101 dB for workers standing on the ground directly below the siren. Assuming that the sound is uniformly emitted, what is the maximum power that the siren can put out? maximium power output: W * TOOLS х10 How far away from the bas and still be able to hear the siren? Neglect any absorption of sound energy by the air; although, in reality, such absorption would be significant at long distances. maximum audible distance: m

Loudspeakers can produce intense sounds with surprisingly small energy input in spite of their low efficiencies. Calculate the power input needed to produce a 90.0-dB sound intensity level for a 12.0-cmdiameter speaker that has an efficiency of 1.00%. (This value is the sound intensity level right at the speaker.)

A 60 year old person has a threshold of hearing at f=10 kHz of 79.0 dB. In contrast, a typical young adult's threshold at 10 kHz is only =43.0 dB. If the young adult can just barely hear a 10 kHz tone, by what factor must the intensity of the sound wave be amplified so that it is heard by the older person?