Q 11-03-115JEE MainJEE Main 2022 (26 Jul, Shift 1)Easy
Two projectiles thrown at $30^\circ$ and $45^\circ$ with the horizontal respectively reach the maximum height in the same time. The ratio of their initial velocities is
Answer: (C) $\sqrt2 : 1$
Time to reach the top is $\dfrac{u\sin\theta}{g}$, so $u_1\sin30^\circ = u_2\sin45^\circ$:
$$\frac{u_1}{u_2} = \frac{\sin45^\circ}{\sin30^\circ} = \frac{1/\sqrt2}{1/2} = \sqrt2$$
Solution by Sreeraj P, M.Sc Physics