Trigonometric Equations Question 140
Question: An observer on the top of a tree, finds the angle of depression of a car moving towards the tree to be 30oo. After 3 minutes this angle becomes 60o. After how much more time, the car will reach the tree
Options:
A) 4 min.
B) 4.5 min.
C) 1.5 min.
D) 2 min.
Show Answer
Answer:
Correct Answer: C
Solution:
- $ d=h\cot 30^{o}-h\cot 60^{o}\text{ and time }= $ 3 min.
$ \therefore $ Speed = $ \frac{h(\cot 30^{o}-\cot 60^{o})}{3} $ per minute It will travel distance $ h\cot 60^{o} $ in $ \frac{h\cot 60^{o}\times 3}{h(\cot 30^{o}-\cot 60^{o})} $ = 1.5 minute.
BETA
