If the distance from a point source of sound is tripled, by what factor does the sound intensity decrease?
(there are no nearby refelctions)
Thanks!
2007-03-26 13:43:31 · 2 answers · asked by Anonymous in Science & Mathematics ➔ Physics
You really need one more "stipulation", and that is that there is no refraction involved.
In this case, if the distance is tripled, then the intensity, which drops as 1/r^2, is cut by a factor of 9.
Picture a sphere: its surface area is multiplied by 9 when its radius triples, and therefore the same amount of sound must be 1/9th as intense for any unit area on the surface of the sphere.
2007-03-26 13:48:03 · answer #1 · answered by firefly 6 · 0⤊ 0⤋
Air molecules absorb some of the vibrations; the greater the distance, the more the amplitude of the sound wave decreases and finally diminishes.
2007-03-26 13:48:45 · answer #2 · answered by Sdrawkcab 2 · 0⤊ 0⤋