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Question
Answer the following question in your own words.
What factors are important to get a distinct echo?
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Solution
- Ambient temperature and the distance between the sound source and the reflecting surface are two factors that are important in the formation of echoes.
- The speed of sound in air at 22°C is 344 m/s. Our brain retains a sound for 0.1 seconds, so only if the sound reaches the barrier and reaches the listener's ears after more than 0.1 seconds will we hear it as a separate sound.
- Distance = Speed × Time
= 344 m/sec × 0.1 sec
= 34.4 m
Thus, the distance from the source of the sound to the obstacle and back to the source is the distance that the sound must travel at least 34.4 m. - So the minimum distance from the sound source to the obstacle should be half of the above distance i.e. 17.2 meters to hear a clear echo.
- These distances are different at different temperatures.
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