Question

An echo is not heard in a small room but it can be heard in hills near ravines.​

Answer 1

Answer: A sound persists in our ear for 0.1s . At temperature 22° C in air and speed of sound 344ms  ⁻¹ , the total distance covered by sound between the point of generation and reflecting surface should be at least (344m/s)×0.1s=34.4m . Thus, the minimum distance between the point of generation and reflecting surface should be half of it i.e. 17.2m . So, we cannot hear an echo in a small room as the minimum distance for the echo will not be satisfied. But we can hear an echo in a long gallery and big halls

Answer 2

Answer:

because sound reflects and comes back faster in a small room

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