मराठी

If the Height of a Vertical Pole is 3–√ Times the Length of Its Shadow on the Ground, Then the Angle of Elevation of the Sun at that Time is (A) 30° (B) 60° (C) 45° (D) 75° - Mathematics

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प्रश्न

If the height of a vertical pole is 3–√3 times the length of its shadow on the ground, then the angle of elevation of the Sun at that time is
(A) 30°
(B) 60°
(C) 45°
(D) 75°

उत्तर

Let AO be the pole and OB be its shadow.
Let the length of the shadow be x.
Let θ be the angle of elevation of the Sun at that time.
Given:
Height of pole (h) =\[\sqrt{3} \times\] Length of its shadow

\[\Rightarrow h = \sqrt{3}x\]

We have:

\[\tan \theta = \frac{AO}{OB}\]

\[ = \frac{h}{x}\]

\[ = \frac{\sqrt{3}x}{x}\]

\[ = \sqrt{3}\]

\[ \Rightarrow \tan \theta = \tan 60^o\]

\[ \Rightarrow \theta = {60}^\circ\]

Thus, the angle of elevation of the Sun is 60°.
Hence, the correct option is B.

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2013-2014 (March) Foreign Set 3

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