Trigonometryhard · Past Paper
From a point on the ground, the angle of elevation of a jet plane is 60°. After a flight of 15 seconds, it becomes 30°. If plane flies at 1500√3 m, find speed.
A200 m/s
B100 m/s
C150 m/s
D300 m/s
✓ Correct Answer: A — 200 m/s
d1 = 1500√3 / tan 60 = 1500. d2 = 1500√3 / tan 30 = 4500. Distance = 3000. Speed = 3000/15 = 200 m/s.
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