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A HRB=05:30 tomamos azimut de aguja a la estrella Polar = 352º y simultáneamente obtenemos demoras de aguja a los faros de Espartel = 128º y de Trafalgar = 022º. Se pide la situación obtenida a HRB 05:30At HRB 05:30 you take a compass azimuth of Polaris = 352º while simultaneously taking compass bearings Da Spartel = 128º and Da Trafalgar = 022º. Find your position at HRB 05:30:
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Correct answer: b) 36º 00' N - 006º 10' W
Why it is correct
With compass azimuth of Polaris Za = 352º, total compass error is Ct = 360º − 352º = +8º. Thus true bearings are Dv(Spartel) = 128º + 8º = 136º (reciprocal 316º) and Dv(Trafalgar) = 022º + 8º = 030º (reciprocal 210º). Both lines intersect at 36º 00′ N, 006º 10′ W.
Why the others are not
- a) Does not add Ct = +8º to the compass bearings before plotting them on the chart.
- c) Does not add Ct = +8º to the compass bearings before plotting them on the chart.
- d) Does not add Ct = +8º to the compass bearings before plotting them on the chart.
How to work it out in the exam
- Compute Ct = 360º − 352º = +8º and true bearings: Dv(Spartel) = 136º and Dv(Trafalgar) = 030º.
- Plot their reciprocals (316º from Spartel and 210º from Trafalgar): they intersect at 36º 00′ N, 006º 10′ W.
Where this question comes from
- Región de Murcia · 2025 · 2ª convocatoria · PY Tipo 1 · question 38 Official paper · Official answer key
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Pending instructor review. Machine translation, not reviewed.