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Question
When a sound is reflected from a distant object, an echo is produced. Let the distance between the reflecting surface and the source of sound production remains the same. Do you hear echo sound on a hotter day?
Solution
An echo is heard when the time interval between the original and reflected sounds is at least 0.1 s. The speed of sound in a medium increases with an increase in temperature. Hence, the time interval between the original sound and the reflected sound will decrease on a hotter day. Therefore, an echo can be heard only if the time interval between the original sound and the reflected sound is greater than 0.1 s.
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