The highest frequency humans can hear is about 20,000 Hz. What is the wavelength of sound in air at this frequency? What is the wavelength of the lowest sounds we can hear, about 20 Hz?
Solution 1P The speed of the sound in normal pressure and temperature is given by c = 340 m/s Now we know that the relationship between speed, frequency and wavelength is given by Part I If the frequency of the sound is f = 20000 Hz, then we can write that So, when the frequency of the sound is 20,000 Hz, the wavelength is 0.017 m. Part II In this case, the frequency of the sound is f = 20 Hz. So using this formula we can write that When the frequency of the sound is 20 Hz the wavelength of the sound is 17 m.