You depart LAT 49°38'N, LONG 152°49'E, for...

Question 1 / 2707066636eea28f7522a1c51b07a

Question 1 of 2707066636eea28f7522a1c51b07a

You depart LAT 49°38'N, LONG 152°49'E, for LAT 49°38'N, LONG 176°12'E. What are the course and distance by parallel sailing?

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Question 1 of 27070

You depart LAT 49°38'N, LONG 152°49'E, for LAT 49°38'N, LONG 176°12'E. What are the course and distance by parallel sailing?

🔍 Key Concepts

• Parallel sailing keeps the same latitude; only longitude changes • Difference of longitude (DLo) must be converted to minutes of arc along that parallel using the cosine of the latitude • 1 minute of arc of longitude at a given latitude = cos(latitude) nautical miles

💭 Think About

• First, determine whether you are going east or west in longitude between the two positions, and think about what that means for the true course (090°T vs 270°T) • Compute the total difference of longitude in degrees and minutes between 152°49'E and 176°12'E, staying on the same side of the 180° meridian; then think about how to turn that DLo into distance at 49°38'N • Ask yourself: if you sailed due east or due west along a parallel at higher latitude, is one degree of longitude more than, less than, or equal to 60 NM?

✅ Before You Answer

• Be sure you calculate the difference of longitude correctly in degrees and minutes • Use the correct formula: $\text{Distance (NM)} = \text{DLo (minutes)} \times \cos(\text{Lat})$ • Confirm that your final distance is reasonable for crossing that many degrees of longitude at about 50°N (not as large as at the equator, where it would be 60 NM per degree)

Question 1 of 27070

You depart LAT 49°38'N, LONG 152°49'E, for LAT 49°38'N, LONG 176°12'E. What are the course and distance by parallel sailing?

090°T, 909 miles

090°T, 1204 miles

270°T, 909 miles

270°T, 1204 miles

Question 1 / 2707066636eea28f7522a1c51b07a

Question 1 of 2707066636eea28f7522a1c51b07a

You depart LAT 49°38'N, LONG 152°49'E, for LAT 49°38'N, LONG 176°12'E. What are the course and distance by parallel sailing?

Back

Question 1 of 27070

You depart LAT 49°38'N, LONG 152°49'E, for LAT 49°38'N, LONG 176°12'E. What are the course and distance by parallel sailing?