Q 11-07-010NEETNEET 2021Top questionEasy
The escape velocity from the Earth's surface is $v$. The escape velocity from the surface of another planet having a radius, four times that of Earth and same mass density is :
Answer: (A) $4v$
Concept. At fixed density $v_e = R\sqrt{\dfrac{8\pi G\rho}{3}} \propto R$.
Step 1. Scale. Four times the radius: $4v$.
Answer. $4v$ (Option A).
Solution by Sreeraj P, M.Sc Physics