Calculate the minimum speed required by a rocket to pull out of the gravitational force of Mars. Given that the earth has a mass `9` times and radius twice of the planet Mars. Escape speed on the surface of earth is `11.2 km s^(-1)`.

Explanation

For earth, `upsilon_(e) = sqrt((2 Gm_(e))/(R_(e)))`
`= 11.2 km s^(-1)`
For Mars, `upsilon_(m) = sqrt((2 GM_(m))/(R_(m))) = sqrt((2G (M_(e)//9))/(R_(e)//2))`
`= sqrt((4)/(9) (GM_(e))/(R_(e))) = (sqrt(2))/(3) upsilon_(e) = (1.414 xx 11.2)/(3)`
`= 5.279 km s^(-1)`