The sound level 23.8 m from a loudspeaker is 66.7 dB. What is the rate at which sound energy is produced by the loudspeaker, assuming it to be an isotropic source?

A sound wave at 20° C has pressure amplitude of 2.00 Pa. The density of air is 1.2 Kg/m and the threshold for hearing intensity is 1012 w/m2. The speed of sound in air is 344 m/s. (a) Find the intensity of the sound wave. (b) Find the intensity in decibels.

the output power of a spherically symmetric sound source is 6.0 W. the decibel level at a distance d from the source is 88 dB. what is d (in meters)?

Problem 9:  One day when the speed of sound in air is 343 m/s, a fire truck traveling at vs = 34 m/s has a siren which produces a frequency of fs = 438 Hz.Randomized Variables vS = 34 m/sf = 438 Hz       Part (a) What frequency (in Hertz) does the driver of the truck hear?Numeric   : A numeric value is expected and not an expression.fd = __________________________________________Part (b) What frequency (in Hertz) does an observer hear when the truck is moving away?Numeric   : A numeric value is expected and not an expression.fo = __________________________________________   Problem 10:  A student knows that an ambulance siren has a frequency of fs = 395 Hz. He measures, when the ambulance is approaching him, the frequency fo = 416 Hz. Assume the speed of sound is 343 m/s in this problem.       Part (a) Input an expression for the ambulance's speed, vs, in terms of the frequencies and the speed of sound v.Expression   :vs =…

One of the loudest sound generators ever created is the Danley Sound Labs Matterhorn. When run at full power, the device uses an input power of 40,000 W. The output power registers 94 dB at 250 m. What is the efficiency of this device— that is, the ratio of output power to input power?

The scream of a little screaming monster reaches the near-side of a sound-insulating wall with an intensity of 95 dB.   The manufacturer of the wall claims the material in the wall will reduce the sound energy by 99%. If this is true, what intensity, in decibels, of sound will be heard on the other side of the wall?

A bell produces sound energy at a rate of 0.3 mW and radiates it uniformly in all directions. What is the intensity level β of the wave 20 m from the bell?

The low-frequency speaker of a stereo set produces 10.0 W of acoustical power. If the speaker projects sound uniformly in all directions, at what distance from the speaker is the intensity level 80.0 dB?

What is the speed of sound in (m/s) in a medium where a 156 KHZ frequency produces a 3.282 cm wavelength?

If a machine produces sound with an intensity level of 97.1 dB, what would its intensity level have to be to reduce the intensity by a factor of 2.40?