Four identical glass test tubes are filled with water to different heights: Tube A ($2$ cm), Tube B ($5$ cm)…
Four identical glass test tubes are filled with water to different heights: Tube A ($2$ cm), Tube B ($5$ cm), Tube C ($10$ cm), and Tube D ($15$ cm). When air is blown horizontally across the mouth of each tube, which tube produces sound with the highest pitch?
Tube A
Tube B
Tube C
Tube D
Solution
Tube D has the highest water level, which leaves the shortest air column above it. A shorter air column vibrates faster (higher frequency), producing a sound with a higher pitch.