JEE Main 12 Jan 2019 Morning Question 21
Question: A person standing on an open ground hears the sound of a jet aeroplane, coming from north at an angle $ 60{}^\circ $ with ground level. But he finds the aeroplane right vertically above his position. If v is the speed of sound, speed of the plane is [JEE Main Online Paper Held On 12-Jan-2019 Morning]
Options:
A) v
B) $ \frac{\sqrt{3}}{2}v $
C) $ \frac{2v}{\sqrt{3}} $
D) $ \frac{v}{2} $
Show Answer
Answer:
Correct Answer: D
Solution:
- $ v _{p}=v,\cos 60^{o} $ $ =\frac{v}{2} $
