Hover or tap underlined Spanish terms to see their translation and exam tip.
Hallar el azimut náutico y la altura estimada de un astro, siendo la latitud del observador 25º00,0’N, la declinación del astro 38º47,3’ y el horario del lugar 351º 18,9’.Find the azimuth and computed altitude of a body when the observer's latitude is 25º 00.0’ N, the body's declination is 38º 47.3’ N, and the local hour angle is 351º 18.9’.
Show the answer
Correct answer: c) Zv = N25.9E and ae = 74º 23.0’.
Why it is correct
The meridian angle is P = 360º − 351º 18.9′ = 8º 41.1′ E. With sin ae = sin(25º) sin(38º 47.3′) + cos(25º) cos(38º 47.3′) cos(8º 41.1′) = 0.96308 we get ae = 74º 23.0′; and tan Z = sin P / (cos l tan d − sin l cos P) = 0.4858 gives Zv = N 25.9º E.
Why the others are not
- a) Miscalculates both the computed altitude and the azimuth.
- b) Gets a computed altitude nearly half a degree too low.
- d) Gets the right altitude but is off by more than 2º in the azimuth.
How to work it out in the exam
- hL = 351º 18.9′ → P = 8º 41.1′ E; since d > l, the body bears NE.
Where this question comes from
- Ministerio de Transportes (Madrid) · 2021 · Convocatoria de febrero · CY Test 2 · question 16 Official paper · Official answer key
Pending instructor review. Machine translation, not reviewed.