Discussion
Phugoid data recorded for one aeroplane at two trim speeds in level flight.
| Case | Trim speed | Measured period |
|---|---|---|
| 1 | 120 m/s | 54 s |
| 2 | 240 m/s | 108 s |
What do the two records confirm about the phugoid?
Answer: A
Doubling the speed has doubled the period, so the period is directly proportional to trim speed, exactly as \( T = \sqrt{2}\pi u_0/g \) predicts. Both records also satisfy the \( T \approx 0.45\,u_0 \) shortcut, which is a quick check that the data are self-consistent. Independence of speed is contradicted by the table itself. A square law would have taken the period to 216 s. An inverse relation would have halved it to 27 s, and is the behaviour of the short period rather than the phugoid, which is a distinction worth fixing firmly.
No comment is present. Be the first to comment.
Loading…
Post your comment
Please log in or register to post a comment.
Examination Categories
- SSC Exams
- Banking Exams
- Teaching Exams
- Civil Services Exams
- Railways Exams
- Engineering Recruitment Exams
- Defence Exams
- State Government Exams
- Police Exams
- Insurance Exams
- Nursing Exams
- Other Government Exams
- NRA CET
- PG Entrance Exams
- Campus Placement
- MBA Entrance Exams
- CUET and UG Entrance
- Judiciary Exams
- Regulatory Body Exams
- Software Development