Q 11-03-033NEETJEE MainMedium
Two balls are projected from the same point with the same speed of $40$ m/s at complementary angles of projection. The sum of their maximum heights is ($g = 10\ \text{m/s}^2$)
Answer: (B) $80$ m
$$H_1 + H_2 = \frac{u^2\sin^2\theta}{2g} + \frac{u^2\cos^2\theta}{2g} = \frac{u^2}{2g} = \frac{1600}{20} = 80\ \text{m}$$
(Both balls have the same range, and this sum does not depend on $\theta$.)
Solution by Sreeraj P, M.Sc Physics