5 Views

Question : The angle of elevation of an aeroplane from a point on the ground is 60°. After flying for 30 seconds, the angle of elevation changes to 30°. If the aeroplane is flying at a height of 4500 metres, then what is the speed (in m/s) of an aeroplane?

Option 1: $50\sqrt3$

Option 2: $100\sqrt3$

Option 3: $200\sqrt3$

Option 4: $300\sqrt3$


Team Careers360 12th Jan, 2024
Answer (1)
Team Careers360 21st Jan, 2024

Correct Answer: $100\sqrt3$


Solution :
Given: The angle of elevation of an aeroplane from a point on the ground is 60° and the height is 4500 metres.
Let the base length be $B_{1}$ when the elevation is 60° and the Base length is $B_{2}$ when the elevation is 30°.
$\tan \ 60° = \frac{4500}{B_{1}}$
$⇒B_{1} = \frac{4500}{\sqrt{3}}$
Now, the angle of the elevation of the aeroplane is changed to 30°.
$\tan \ 30° = \frac{4500}{B_{2}}$
$⇒B_{2} = 4500\sqrt{3}$
For the speed of the aeroplane,
$\text{Speed} = \frac{\text{Distance}}{\text{Time}}= \frac{B_2 \:–\: B_{1}}{30} = \frac{4500\sqrt{3} \:–\: (\frac{4500\sqrt{3}}{3})}{30} = 100\sqrt{3}$ m/s
Hence, the correct answer is $100\sqrt{3}$.

SSC CGL Complete Guide

Candidates can download this ebook to know all about SSC CGL.

Download EBook

Know More About

Related Questions

TOEFL ® Registrations 2024
Apply
Accepted by more than 11,000 universities in over 150 countries worldwide
Manipal Online M.Com Admissions
Apply
Apply for Online M.Com from Manipal University
View All Application Forms

Download the Careers360 App on your Android phone

Regular exam updates, QnA, Predictors, College Applications & E-books now on your Mobile

150M+ Students
30,000+ Colleges
500+ Exams
1500+ E-books