Q 11-03-079JEE MainJEE Main 2023 (29 Jan, Shift 1)Easy
A stone is projected at angle $30^\circ$ to the horizontal. The ratio of kinetic energy of the stone at point of projection to its kinetic energy at the highest point of flight will be
Answer: (D) $4:3$
At the highest point only the horizontal component $u\cos30^\circ$ remains.
$$\frac{K_i}{K_{top}}=\frac{u^2}{u^2\cos^2 30^\circ}=\frac{1}{3/4}=\frac{4}{3}$$
Solution by Sreeraj P, M.Sc Physics