* Resonance and Wavelength: Resonance occurs when the length of a tube is a multiple of half the wavelength of the sound wave. This creates standing waves within the tube, where the wave reflects back and forth, amplifying the sound.
* Shorter Length, Shorter Wavelength: When the tube is shortened, the wavelength of the sound wave that can resonate within it also needs to be shorter to fit the new length.
* Higher Frequency: Since the relationship between wavelength and frequency is inverse (wavelength = speed of sound / frequency), a shorter wavelength means a higher frequency.
* Higher Pitch: Higher frequency sound waves are perceived as having a higher pitch.
In summary: Shortening the tube forces the resonant sound wave to have a shorter wavelength, which results in a higher frequency and a higher pitch.
