Question

A person fires a gun standing at a distance of 55m from a wall. If the speed of sound is 330 m/s find the time for an echo to be heard??​

Answer 1

Given:-

→ Distance of the wall from the person = 55m

→ Speed of sound = 330 m/s

To find:-

→ Time after which the echo is to be heard.

Solution:-

Let the required time be 't' seconds.

Now, we know that :-

If 'd' is the distance of the person from the wall, then total distance travelled by the wave in time interval 't' is '2d' .

∵ Speed = Distance/Time

⇒ v = 2d/t

⇒ vt = 2d

∴ t = 2d/v

Where :-

• v is the speed of sound.

• t is required time.

• d is the distance.

Substituting values, we get :-

⇒ t = 2×55/330

⇒ t = 110/330

⇒ t = 0.33 s

Thus, the echo is to be heard after 0.33s .

Some Extra Information:-

If we go to an auditorium which is empty and we call our name, we hear the name coming back after a short while. This is because of reflection of sound- the phenomenon is called "echo".

We can say that, 'echo is the repitition of sound due to reflection of sound waves back towards the source'.

Answer 2

that's all take care bye