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The shadow of a tower at a time t is 3 times longer than its shadow when the angle of elevation of the sun is 60 degrees. The angle of elevation at time t is
A60 degrees
B15 degrees
C45 degrees
D30 degrees
Answer & Solution
Correct answer: D. 30 degrees
1. When sun is at 60 degrees, shadow = h/tan(60) = h/(square root of 3).
2. New shadow = 3 × h/(square root of 3) = h × square root of 3.
3. tan(new) = h / (h square root of 3) = 1/(square root of 3); so new = 30 degrees.
_Source: NCERT Class 10 Mathematics, Ch 9 "Some Applications of Trigonometry", §9.2_
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