Question

what is an eacho how is eacho formed​

Answer 1

Answer:

an eacho means refraction of our or other voices it formed due to the empty room with the help of air

Answer 2

Answer:

Echo is the reverse sound which is heard after the sound waves produced by your mouth hits hurdle and comes back to us.

Eco is found only when the hurdle is 17.2 metres away from us because of the following reason

The speed of sound wave in air at 22 degree celsius is 344m/s. and the sound produced by our mouth persists for 0.1 second in our mind. Hence the distance travelled by a sound wave should be

344 * 0.1 = 34.4

therefore the hurdle should be 17.2 m away