Question
Kelvin and Helmholtz name a form of this condition that arises when adjacent layers of a fluid with different densities flow at different speeds. For 10 points each:
[10m] Name this condition in which disturbances at fluid interfaces grow more extreme over time on their own.
ANSWER: instability [or fluid instability or Kelvin–Helmholtz instability or interface instability; accept word forms like unstable; prompt on turbulence or turbulent flow by asking, “what condition causes turbulence in this case?”]
[10h] The Taylor–Goldstein equation describes Kelvin–Helmholtz instability in part by assuming that density variations only affect this force. The Brunt–Väisälä (“BROONT VAE-sa-la”) frequency is also known as the “frequency” of this gravitational force.
ANSWER: buoyant force [or buoyancy; prompt on upthrust]
[10e] Buoyant force equals the negative product of volume, density, and this quantity that approximately equals 9.8 meters per second squared.
ANSWER: little g [or acceleration due to gravity or gravitational acceleration or lowercase g; prompt on g]
<Ganon Evans, Science - Physics> ~23803~ <Editor: David Bass>
Data
Summary
| Tournament | Edition | Exact Match? | Heard | PPB | Easy % | Medium % | Hard % |
|---|---|---|---|---|---|---|---|
| 2024 PACE NSC | 06/08/2024 | Y | 36 | 14.44 | 92% | 31% | 22% |