Sound intensity Definition and 117 Threads

Homework Statement A person is a certain distance away from a plane with three equally noisy engines at 120 dB. What is the sound intensity if two of the engines are shut off? Homework Equations B (in dB) = log I/Io The Attempt at a Solution using this equation: 120 dB = 10 log...

This problem for some reason is giving me serious problem: A 1.00 kHz tone issued from a loudspeaker has an intensity of 100. dB at a distance of 2.50 meters. If the speaker is assumed to be a point source, how far from the speaker will the sound (a) have an intensity of 60.0 dB and (b) be...

You are trying to overhear a juicy conversation, but from your distance of 25.0 m , it sounds like only an average whisper of 25.0 dB . So you decide to move closer to give the conversation a sound level of 80.0 dB instead. how close should you come? d= ...

Hi I have a question here from a chapter on sound. I'm not sure on how to solve this, so I was wondering if someone here could please give me a hand. Thank You! Question: A point source at A emits sound uniformly in all directions. At point B, the listener measures the sound intensity to...

Homework Statement The howler monkey is the loudest land animal and can be heard up to a distance of 1.4 km. Assume the acoustic output of a howler to be uniform in all directions. The distance at which the intensity level of a howler's call is 49 dB, in SI units, is closest to: a...

A recording engineer works in a soundproofed room that is 36.2 dB quieter than the outside. If the sound intensity in the room is 2.45 x 10-10 W/m2, what is the intensity outside? It seems so ez yet I'm getting the wrong answer ok so here is what I am able to do the difference of 36.2dB...

I am having trouble with these two problems.. 1.By how many decibels do you reduce the sound intensity level due to a source of sound if you quadruple your distance from it? Assume that the waves expand spherically. For this one do I have to find ratios of I1/I2 and then substitute it in...

the pain threshold of your ears is about 130 phon.The sound levelclose to a jet (r=1m) when it takes off is about 150 phon.How far do you have to go away in order to lower the intensity level below the pain threshold?? anyone pls tell me the formula to use so that i can calculate as i can't...

Hello. I am totally stuck on this question. I don't even know where to begin. Any help would be appreciated: A spherical sound source is placed at P1 near a reflecting wall and a microphone is located at P2. The frequency of the sound source is variable. Find the two lowest frequencies for...

consider a piston in an engine with a stroke of 86 mm and RPM 8000 which gives the frequency of sound it is producing(due to compression and decompression) to be 133 Hz and wavelength 2.57 m. Then the pressure amplitude turns out to be 20000 Pa and the intensity of the sound wave to be...

I am confused about a homework problem and was hoping that maybe somebody here can help... Homework Problem When a helicopter is hovering 1090 m directly overhead, an observer on the ground measures a sound intensity I. Assume that sound is radiated uniformly from the helicopter and that...

:confused: A loudspeaker supported well above the ground on a post is supplied with 8.5 W of electrical power. The speaker is able to convert 5.6% of that into sound power. (That number is known as the speaker's efficiency.) If we assume that sound radiates equally in all directions...

sound intensity level can be measured in dB & dB (A). What is the difference between the 2 scales?

I have no idea what I'm doing wrong on this one. I'm having problems somewhere in the log conversions to W/m^2 I believe. A siren mounted on the top of towers produces a noise of 120 dB at a distance of 2 meters. Treating the siren as a point particle (and ignoreing reflection and...

The upper limit of the intensity level of sound waves is about 194 dB. This intensity corresponds to 100% modulation of the air; that is, the amplitude of the pressure oscillations corresponds to that of atmospheric pressure. What intensity (W/m^2) would be required to generate this level of...

If 2 flutist play their instruments together at the same intensity, is the sound twice as loud as that either flutist playing alone at that intensity? Why or why not?

The problem states: A microphone in the ocean is sensitive to sounds emitted by popoises. To produce a usable signal , sound waves striking the microphone must have an intesity of 10.6 dB. If porpoises emit sound waves with a power of 0.0502 W, how far can a porpoise be from the microphone and...