An echo is returned in 6 seconds. What is the distance of reflecting surface from source? [Given that speed of sound is 342 m/s.]

Given, 

Time in which echo returned, t = 6 s, 

Speed of sound, v = 342 m/s 

Distance = Speed × Time = 342 × 6 = 2052m 

As this distance is twice the distance of reflecting surface from source. 

So, 

The distance of reflecting surface from source = 2052 / 2 = 1026 m.

Given 

Speed of sound (u) = 342 m/s 

Time taken for hearing the echo (t) = 6 s 

Now

speed= \(\frac{distance}{time}\) 

⇒ 342 =\(\frac{distance}{6}\)  

⇒ Distance travelled by the sound = 342 ×6 = 2052 m.

In 6s, sound has to travel twice the distance between the source and reflecting surface. Therefore, the distance of the reflecting surface from the source =\(\frac{2052}{2}\) = 1026 m

Distance of reflecting surface = 1026 m.