Question

An echo returns in 30 s. What is the distance of the reflecting surface from the source?

Given that speed of sound= 342m/s

• A. 5100 m
• B. 22.66m
• C. 5130 m
• D. 22.8 m

Answer 1

The correct option is C 5130 m

Time taken by the wave to travel from the sound to the reflecting surface $=t=\frac{30}{2}=15m$
Speed $=342m/s$
Distance of reflecting surface from the sound $=342\times 15=5130m$