Question
The “Chandler wobble” is this curve applied to the Earth’s rotation. For 10 points each:
[10h] Name this curve traced out on Poinsot’s (“pwann-SOH’s”) ellipsoid, useful for visualizing the motion of rigid bodies with three unequal moments of inertia. A related curve traced out on the invariable plane prefixes “her-” to this word.
ANSWER: polhode (“PAWL-hode”) [or herpolhode]
[10m] The polhode is traced by this quantity on Poinsot’s ellipsoid. Euler (“OY-ler”) forces are present if this quantity changes for a rotating frame, and this pseudovector is crossed twice in the expression for centrifugal force.
ANSWER: angular velocity [or rotational velocity; prompt on omega; reject “angular speed” or “angular frequency”]
[10e] Poinsot’s ellipsoid is defined as a constant surface of this scalar quantity, which is equal to “one-half capital I times omega squared” for a rotating rigid body.
ANSWER: kinetic energy [or KE; prompt on energy; prompt on T or K]
<Physics>
Summary
| 2024 ACF Regionals @ Berkeley | 01/27/2024 | Y | 3 | 16.67 | 100% | 33% | 33% |
| 2024 ACF Regionals @ Cornell | 01/27/2024 | Y | 3 | 3.33 | 33% | 0% | 0% |
| 2024 ACF Regionals @ JMU | 01/27/2024 | Y | 7 | 4.29 | 29% | 14% | 0% |
| 2024 ACF Regionals @ Minnesota | 01/27/2024 | Y | 2 | 5.00 | 50% | 0% | 0% |
| 2024 ACF Regionals @ Ohio State | 01/27/2024 | Y | 2 | 15.00 | 100% | 50% | 0% |
| 2024 ACF Regionals @ Rutgers | 01/27/2024 | Y | 4 | 20.00 | 100% | 75% | 25% |
| 2024 ACF Regionals @ Imperial | 01/27/2024 | Y | 8 | 11.25 | 63% | 38% | 13% |
| 2024 ACF Regionals @ Vanderbilt | 01/27/2024 | Y | 4 | 10.00 | 75% | 25% | 0% |
| 2024 ACF Regionals @ MIT | 01/27/2024 | Y | 1 | 0.00 | 0% | 0% | 0% |
Data
| Arizona State | Iowa State | 0 | 0 | 10 | 10 |
| Minnesota B | Minnesota C | 0 | 0 | 0 | 0 |