A person has a hearing range from 20 kHz. What is the typical wavelength of sound waves in air corresponding to these two frequencies? Take the speed of sound in air as 344 m s-1?
Given,
Speed, v = 344 m/s
Frequency, f = 20 Hz
Wavelength, λ =?
We know that,
v = f × λ
344 = 20 × λ
λ = 
= 17.2 m (i)
When frequency is 20,000 Hz:
Speed, v = 344 m/s
Frequency, f = 20 kHz
= 20 × 1000 Hz
Wavelength, λ =?
We know that,
v = f × λ
344 = 20000 × λ
λ = 
= 0.0172 (ii)
Therefore, the wavelength of sound in air having frequencies corresponding 20 Hz and 20 kHz are 17.2 m and 0.0172 m respectively.
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