Question

(c) A sound wave travelling in water has wavelength 0.4 m.
Is this wave audible in air? (The speed of sound in water = 1400 ms !)​

Answer 1

Answer:

Given:

Wavelength of sound wave = 0.4 m

Speed of water in water = 1400 m/s

To find:

Whether this sound is audible to human ear or not ?

Concept:

Always remember this data ;

• Sound frequencies in between 20 Hz and 20,000 Hz are audible to human ear.

Calculation:

$\boxed{ \sf{ \bold{ \red{frequency = \dfrac{velocity}{wavelength} }}}}$

$= > freq. = \dfrac{1400}{0.4}$

$= > freq. = 3500 \: hz$

So this sound will be audible to human ear as it falls in the audible range of sound.

Additional information:

• Frequency of any wave depends on the source
• Velocity of wave depends only on 1 parameter i.e. Temperature .
• Change in frequency or wavelength doesn't change the Velocity of the wave.

Answer 2

Answer:

Frequency = 1400/(0.4) = 3500 Hz.

This frequency is within the following range :

$\boxed{ \large{ \sf{ \bold{20hz < 3500hz < 20000hz}}}}$

So this frequency is audible to the human ear.