What do you mean by an echo? State two conditions for hearing a distinct echo.

Discussion in 'CBSE Class 9 Physics Help' started by Vinila Choudary, Feb 29, 2012.

  1. Vinila Choudary

    Vinila Choudary Active Member


    (i) To hear a distinct echo, the time interval between the original sound and the reflected one must be at least 0.1 s.
    (ii) For hearing distinct echoes, the minimum distance of the obstacie from the source of sound must be 17.2 m.
    Echo is a repetition of sound due to the reflection of original sound by a broad and hard obstacle.

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