Factors affecting sound intensity

1. Aug 3, 2014

somecelxis

1. The problem statement, all variables and given/known data

the factor affecting sound intensity is amplitude and frequency . why not also the distance from the source (r) ,

in my opinion, intensity = power/area , so the intensity = power/ 4 pi r ^2 .... so I is inversely proportional to r^2 ...

2. Relevant equations

3. The attempt at a solution

2. Aug 3, 2014

Staff: Mentor

The amplitude and intensity are related. So as distance from the source increases, both amplitude and intensity drop.

3. Aug 3, 2014

somecelxis

do you mean the intensity and 'distence from the source ' is not directly related , so i cant say that Intensuty is directly proportional to 1/'distence from the source' ?

4. Aug 3, 2014

Staff: Mentor

For a point source, the intensity of the sound is inversely proportional to the square of the distance. See: Inverse Square Law for Sound

5. Aug 3, 2014

somecelxis

the link also gives the intensity of the sound is inversely proportional to the square of the distance. So why cant i say intensity of the sound is inversely proportional to the square of the distance? but i can only say the factor affecting sound intensity is amplitude and frequency which means Intensity is directly proportional to amplitude square and frequncy square

6. Aug 3, 2014

somecelxis

or can I say in this way? as the distance from the source incraeses , the amplitude of particle at a partcular point decreases . the decreases in the amplitude causes the intensity to drop? so the Intensity is dependent on amplitude square. beacuse intensity has a 'direct 'reatioship between amplitude.