Sub-topic 1
2026 · National Semifinal
Free
Speed of sound in air as a function of temperature
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Sub-topic 2
2026 · National Quarterfinal
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Sound intensity level in decibels from intensity relative to the reference threshold
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Sub-topic 3
2025 · National Quarterfinal
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Sound intensity from an isotropic point source
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Sub-topic 4
2024 · Regional Championship
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Beat frequency from two sound sources of slightly different frequency
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Sub-topic 5
2003 · National Semifinal
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Diffraction of sound waves around an obstacle or through an opening
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Sub-topic 6
2003 · National Semifinal
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Why a sonic boom is heard only after a supersonic aircraft passes overhead
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Sub-topic 7
2013 · National Preliminary
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Pitch versus mass per unit length of a vibrating string (true/false)
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Sub-topic 8
2013 · National Preliminary
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Pitch versus tension of a vibrating string (true/false)
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Sub-topic 9
2013 · National Preliminary
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Fundamental pitch versus length of a vibrating string (true/false)
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Sub-topic 10
2016 · National Preliminary
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Riddle: ultrasound as a longitudinal mechanical wave beyond human hearing
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Sub-topic 11
2019 · National Preliminary
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Speed of sound from the fundamental frequency of a pipe closed at one end
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Sub-topic 12
2019 · National Preliminary
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Possible frequency of a second note from a given beat frequency
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Sub-topic 13
2022 · National Preliminary
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True or false: radio waves have longer wavelengths than audible sound waves
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Sub-topic 14
2022 · National Preliminary
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True or false: radio waves travel faster than audible sound waves in air
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Sub-topic 15
2022 · National Preliminary
Premium
True or false: radio wave frequency is greater than audible sound wave frequency
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