Factors affecting sound intensity

[somecelxis]

Homework Statement

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 ...

Homework Equations

The Attempt at a Solution

 

[Doc Al]

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

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

 

[somecelxis]

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

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

 

[Doc Al]

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

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

 

[somecelxis]

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

the link also gives the intensity of the sound is inversely proportional to the square of the distance. So why can't 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

 

[somecelxis]

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

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.