A classical mechanics problem by mukesh jha

Classical Mechanics Level 3

Gravitational acceleration on the surface of a planet is \sqrt{6}g/11,where"g"is the gravitational acceleration on the surface of earth..The average mass density of the planet is 2/3 times that of earth.If the escape speed on the surface of the earth is 11 km/sec,the escape speed on the surface of the planet in km/sec will be-----------------