Standing wave of string, sound question

[AA|FCB|DOC]

---

Members don't see this ad.

Can someone please help me clarify some confusion I have with this stuff? So I understand that the wavelength of the string is given by 2L/n and that the wave on the string is transverse. However, the sound wave that hits our ear is longitudinal. So I think (but want to make sure) that the speed of the sound we hear travels at 343 m/s but the speed of the transverse wave on the string IS NOT. Is this correct? And if so, then if wavelength and frequency on the wave on the string can be given by 4L/n, then how do we get wavelength/frequency for the sound we HEAR (the longitudinal wave). Wouldn't the pitch of the sound we hear differ from the frequency of the string's standing wave? Thanks in advance

 

[milski]

Yes, you are correct, the speed of the wave on the string and the speed of sound are different. You probably have encountered that in other situations but what stays constant between the two is the frequency. Since the frequency is the same, the speeds are different, it follows that the wavelength will be different between the wave on the string and the sound wave.

 

[AA|FCB|DOC]

Thank you for the clarification! So just to double check, then if you get the wavelength of the string from lambda= 2L/n then you CANNOT use the the speed of 343 m/s to find frequency, correct? Because then you would be using the speed of the wave in air but wavelength from the string so it would give you the incorrect value. Am I interpreting that correctly? And I am guessing the only conditions you could do this would be for the pipes since they involve air and not strings and therefore you could use 343 for both speeds.

 

[milski]

Thank you for the clarification! So just to double check, then if you get the wavelength of the string from lambda= 2L/n then you CANNOT use the the speed of 343 m/s to find frequency, correct? Because then you would be using the speed of the wave in air but wavelength from the string so it would give you the incorrect value. Am I interpreting that correctly? And I am guessing the only conditions you could do this would be for the pipes since they involve air and not strings and therefore you could use 343 for both speeds.

Yes, that is correct, seems that you got it! 👍