1. The problem statement, all variables and given/known data [A rocket has landed on Planet X, which has half the radius of Earth. An astronaut onboard the rocket weighs twice as much on Planet X as on Earth. If the escape velocity for the rocket taking off from Earth is v , then its escape velocity on Planet X is a) 2 v b) (√2)v c) v d) v/2 e) v/4 C is the answer 2. Relevant equations so I know the following 0.5 * m * (vEscape)^2 - [ (G * m * mEarth)/r ] = 0. 3. The attempt at a solution I know that my g on this planet is going to be twice as much so the radius of this planet is decreased by a factor of (1 / sqrt(2) ) [via newton's law of gravitation]. Thus, I think that planet X's radius should be changed to (1 / sqrt(2) ) * radius of Earth, and that would create a new escape velocity different from v. Could anyone please explain how C is the right answer? Thanks in advance.