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
Concept. For complementary angles, $\sin^2\theta + \cos^2\theta = 1$.
Step 1. Sum.
$$H_1 + H_2 = \frac{u^2}{2g} = \frac{1600}{20} = 80\ \text{m}$$
Answer. $80$ m (Option B).
Solution by Sreeraj P, M.Sc Physics