You depart LAT 25°54'N, LONG 9°38'E and...

Question 1 of 2707066636eea28f7522a1c51b067

You depart LAT 25°54'N, LONG 9°38'E and steam 592 miles on course 270°. What is the longitude of arrival?

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Question 1 of 27070

Q

You depart LAT 25°54'N, LONG 9°38'E and steam 592 miles on course 270°. What is the longitude of arrival?

🔍 Key Concepts

• Difference between a great-circle route and a Mercator sailing when steaming due west or east • Relationship between longitude change, departure, and cosine of latitude: Dep = ΔLong × cos(lat) • Unit conversion between nautical miles, minutes of latitude, and minutes of longitude at a given latitude

💭 Think About

• Are you moving north/south at all on course 270°, or only east/west? How does that affect your latitude and the type of calculation needed? • 592 miles of distance on a parallel of latitude at 25°54'N corresponds to how many minutes of longitude at that latitude? • Based on your starting longitude in degrees East, does traveling on course 270° move you toward East or West longitude?

✅ Before You Answer

• Confirm that course 270° means you are steaming due west along a parallel (constant latitude). • Use the relation Dep (in NM) = ΔLong (in minutes) × cos(lat) and solve for ΔLong. • Convert the change in longitude from minutes to degrees and minutes, then apply it in the correct direction (E or W) from 9°38'E.