The escape velocity from earth surface is 11 ~km / s . The escape velocity from a planet having twice the radius and same mean density as earth is

Step-by-step solution

Escape velocity is given by, aligned v _ e & = 2 GM R & = 2 G R 4 3 R ^3 = 8 G 3 R ^2 = 8 G 3 R aligned As the planets have the same density, aligned & v_ e R & v _ e ^ v _ e = R ^ R = 2 R R =2 & v _ e ^ =2 v _ e =2 11=22 ~km / s aligned