Q. The maximum height attained by a projectile when thrown at an angle $\theta$ with the horizontal is found to be half the horizontal range. Then $\theta$ is equal to

A) $\tan^{- 2}(2)$
B) $\frac{\pi}{6}$
C) $\frac{\pi}{4}$
D) $\tan^{- 1}\ \left( \frac{1}{2} \right)$
Explanation

(a) $Maximum\ height,\ H = \frac{u^{2}\sin^{2}\theta}{2g}$
$Range,\ \ R = \frac{u^{2}sin2\theta}{g}$
$Given,\ \ H = \frac{R}{2}$
$\therefore\ \frac{u^{2}\sin^{2}\theta}{2g} = \frac{u^{2}2sin\theta cos\theta}{2g}$
$or\ \ sin\theta = 2cos\theta$
$or\ \ tan\theta = 2$
$or\ \ \theta = \tan^{- 1}(2)$

Dr. Abubacker
Reviewed by Dr. Abubacker

Physics Educator & NEET/JEE Specialist

Ph.D. in Physics with 19+ years of teaching experience.