Question
Download Solution PDFAn echo returned in 2s. What is the distance of the reflecting surface from the source, given that the speed of the sound is 342 ms-1.
Answer (Detailed Solution Below)
Detailed Solution
Download Solution PDFThe correct answer is 342 m.
CONCEPT:
- Echo: If we shout or clap near a suitable reflecting object such as a tall building or a mountain, we will hear the same sound again a little later. This sound which we hear is called an echo.
- Echoes are heard due to the phenomenon of Reflection of sound waves.
- To hear the echo clearly, the reflecting object must be more than 17.2 m from the sound source for the echo to be heard by a person standing at the source.
CALCULATION:
Speed of sound = 342 m/s.
The time is taken for hearing an echo = 2s.
- The speed of sound is
\(⇒ Speed (v)= \frac{distance (d)}{time (t)}\)
Distance travelled = 2d = v × t
⇒ 2 × d = 342 × 2
⇒ d = (342 × 2)/2
⇒ d = 342 mLast updated on Jul 18, 2025
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