An aeroplane flying at a constant speed, parallel to the horizontal ground, … kmabove it, is obsered at an elevation of … from a point on the ground. If, after five seconds, its elevation from the same point, is …, then the speed (in km / hr) of the aeroplane, is :

Option B. For …OA, A, OA₁ = … = 1 km

Height and Distance

JEE Main 2018 · 15 Apr, Morning shift · Q3909

MathematicsMedium38×since 2004Q3909

An aeroplane flying at a constant speed, parallel to the horizontal ground,

\sqrt 3

kmabove it, is obsered at an elevation of

{60^o}

from a point on the ground. If, after five seconds, its elevation from the same point, is

{30^o}

, then the speed (in km / hr) of the aeroplane, is :