# Homework Help: 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.