Gravitational acceleration on the surface of a planet is $\frac{\sqrt{6}}{11} \mathrm{~g}$, where g is the gravitational acceleration on the surface of the earth. The average mass density of the planet is $\frac{2}{3}$ times that of the earth. If the escape speed on the surface of the earth is taken to be $11 \mathrm{kms}^{-1}$, the escape speed on the surface of the planet in $\mathrm{kms}^{-1}$ will be