Echo is not heard in a small room, why? The speed of sound wave is 350 m/s and its wave length is 5 meter . What is its frequency?
For the creation of an echo, the minimum distance between the source and the object must be 17.2 m. In a small room, this condition is not fulfilled so, echo is not heard.
Solution:
Given,
Velocity = 350 m/s
Wavelength = 5 m
We know,
Velocity = Wavelength * Frequency
or, Frequency = Velocity / Wavelength
= 350 / 5
= 70 Hertz
Hence, the required frequency of the sound wave is 70 Hertz.
