Q. An aircraft is flying at a height of 3400 m above the ground. If the angle subtended at a ground observation point by the aircraft position 10 s apart is $30{^\circ}$, then the speed of the aircraft is
A) ${19.63\ ms}^{- 1}$
B) ${1963\ ms}^{- 1}$
C) ${108\ ms}^{- 1}$
D) ${196.3\ ms}^{- 1}$
Explanation
(d) $tan\theta = \frac{L}{A}$
$\tan 30{^\circ} = \frac{10v}{3400}$
$v = \frac{340}{\sqrt{3}} = 196.3\ m/s$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.