Q 11-09-018NEETJEE MainTop questionHard
A tank standing on the ground is filled with water to a height $H$. A small hole is to be made in its side so that the water jet lands as far from the tank as possible. The hole should be at a height above the ground of
Answer: (A) $\dfrac{H}{2}$
Concept. A hole at height $h$ gives $v = \sqrt{2g(H - h)}$ and fall time $\sqrt{\dfrac{2h}{g}}$; range $x = 2\sqrt{h(H - h)}$.
Step 1. Maximise. $h(H - h)$ is largest at $h = \dfrac{H}{2}$ (range $H$).
Answer. $\dfrac{H}{2}$ (Option A).
Solution by Sreeraj P, M.Sc Physics