Question

If a source of sound and a man are at the same altitude, the sound is heard better in the direction of the wind than in the opposite direction. How can you explain this phenomenon?

Answer 1

Whenever any sound is emitted, the observer always hears it after some time later than the actual time when the sound is emitted. This is due to the time that has got used by the sound in travelling the distance between the source and the observer.

Thus there is always a delay in hearing the sound.

For eg:- The thunder is heard a few seconds after the lightening flashes in the sky, although both take place at the same time.

If wind is blowing in the same direction as that of the sound, then the resultant velocity of the sound is given by the sum of its original velocity and that of the wind.

The resultant velocity is given by the difference between the two, when the wind is in a direction opposite to the sound.

If the wind is in a direction inclined to the sound, then the component of the velocity of the wind which is in the, or opposite to the, direction of the sound should be added or subtracted respectively.

Thus, a sound is heard better in the direction of the wind than in the opposite direction because the delay will be lesser.