Question

when a sound is reflected from a distance object an echo is produced. let the distance between the reflection surface and the source of a sound production remains he. do u hear echo's sound..​

Answer 1

An echo is heard when the time for the reflected sound is heard after 0.1 s

Time Taken= Total Distance / Velocity

On a hotter day, the velocity of sound is more. If the time taken by echo is less than 0.1 sec it will not be heard.

Answer 2

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As the sensation of sound persists in our brain for about 0.1 s.To hear a distinct echo the time interval between the original sound and the reflected one must be at least 0.1s. There for the total distance covered by the sound from the point of generation to the reflecting surface and back should be at least

(344m/s) x 0.1s = 34.4 m.

Thus, for hearing distinct echoes, the minimum distance of the obstacle from the source of sound must be half of thisdistance, that is, 17.2 m. The speed of sound will increase with an increase in temperature.

Therefore, on a hotter day speed of sound will be greater hence reflected sound will reach us before 0.1 seconds.As a result, there will be no distinct echo will be heard by us.

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