Calculating Frequency of Sound Wave in Water

[jazzchan]

Dear all,

if a sound wave of 1.0 kHz in air strikes the surface of a lake and penetrates into water. How can find the frequency of the wave in water ?? and assume the speed of sound in water is 1500 m/s for all frequencies !

the frequency in air is equal to the frequency in water ??

thanks

jazz

 

[HallsofIvy]

The wavelength, however, will change. Frequency, in cycles per second, times wavelength, in meters per cycle is always equal to the wave speed, in meters per second. Since sound travels faster in water, the waves "stretch out".

 

[M98Ranger]

Dear jazz,

To calculate the frequency of a sound wave in water, we can use the formula: frequency = speed of sound in water / wavelength of sound in water.

Since the speed of sound in water is given as 1500 m/s for all frequencies, we can use this value in our calculation. However, the wavelength of the sound wave will change when it enters water due to the change in medium.

To find the wavelength of the sound wave in water, we can use the formula: wavelength in water = wavelength in air / refractive index of water. The refractive index of water is approximately 1.33.

Using this information, we can calculate the frequency of the sound wave in water by dividing the speed of sound in water (1500 m/s) by the wavelength in water. This will give us the frequency of the sound wave in water, which will be different from the frequency in air due to the change in medium.

So, to answer your question, the frequency of the sound wave in water will not be equal to the frequency in air. It will be lower due to the change in wavelength.

I hope this helps. Let me know if you have any further questions.