Q 11-07-103JEE MainJEE Main 2023 (13 Apr, Shift 1)Easy
A planet having mass $9M_e$ and radius $4R_e$, where $M_e$ and $R_e$ are mass and radius of earth respectively, has escape velocity in $\text{km s}^{-1}$ given by (Given escape velocity on earth $V_e=11.2\times10^3\ \text{m s}^{-1}$)
Answer: (B) 16.8
$v\propto\sqrt{\dfrac MR}=\sqrt{\dfrac94}=1.5$, so $v=16.8\ \text{km s}^{-1}$.
Solution by Sreeraj P, M.Sc Physics