Celestial Navigation · Time — Arc to Time
Convert a longitude of 75°15'W to its equivalent in time (the conversion of arc to time at 15° per hour).
- A5h 15m 00s
- B5h 01m 00s✓ Correct
- C4h 59m 00s
- D7h 30m 00s
Explanation
15° = 1 hour, so 75° = 5h 00m. Then 1' of arc = 4 seconds of time, so 15' = 60s = 1m. Total: 5h 01m 00s. The Nautical Almanac includes an arc-to-time table for exactly this conversion.
Authority: Nautical Almanac, conversion of arc to time; Bowditch (Pub. No. 9)
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