Hover or tap underlined Spanish terms to see their translation and exam tip.
Calcular la distancia ortodrómica entre: Situación A: 19°42,0´N; 112°09,0´W Situación B: 20°18,0´N; 154°15,0´WCalculate the great-circle distance between Position A (19° 42.0' N, 112° 09.0' W) and Position B (20° 18.0' N, 154° 15.0' W).
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Correct answer: c) 2367.4 miles
Why it is correct
With ΔL = 42º 06.0′ and both latitudes north, cos D = sin(19º 42′) sin(20º 18′) + cos(19º 42′) cos(20º 18′) cos(42º 06′) = 0.77211. That gives D = 39.456º, or 2367.4 miles when multiplied by 60.
Why the others are not
- a) Does not match the spherical law of cosines result.
- b) Subtracts the sine product as if the latitudes had opposite names.
- d) Corresponds to the approximate rhumb-line distance, which exceeds the great-circle distance.
How to work it out in the exam
- cos D = sin l1 sin l2 + cos l1 cos l2 cos ΔL; multiply D in degrees by 60.
Where this question comes from
- Ministerio de Transportes (Madrid) · 2019 · Convocatoria de junio · CY Test 1 · question 19 Official paper · Official answer key
- Ministerio de Transportes (Madrid) · 2019 · Convocatoria de junio · CY Test 2 · question 12 Official paper · Official answer key
Pending instructor review. Machine translation, not reviewed.