Question

An echo of a sound is heared after 5 sec if the speed of sound in air is 342m/s calculate the distance of the reflecting surface

Answer 1

Hello Mate!

Since we know that, while we hear reflected sound there,

s = 2d / t

Then, 2d = s × t

This is because it is the distance travelled by sound to object and then getting back to its source after reflection.

So according to question, time taken is 5 secs and speed is 342 m/s of sound in air.

2d = 342 m/s × 5s

2d = 1710 m

d = 1710 m / 2

d = 855 m

Hence distance between source and object is 855 m.

Thanks!!!

Have great future ahead!

Answer 2

here is your answer OK ✌✌

Speed of sound, v = 342 m s−1

Echo returns in time, t = 3 s

Distance travelled by sound = v × t = 342 × 5 = 1710m

In the given time interval, sound has to travel a distance that is twice the distance of the reflecting surface and the source.

Hence, the distance of the reflecting surface from the source

Speed = 342 m / s
Time = 5 sec
Distance = Speed * time
= 342 * 5
= 1710 m


then 1710/2 because of distance 2 so 855 answer