Orbital velocity: It is the velocity acquired by an object to orbit around any celestial body. The orbital path is a balance between gravity of the celestial body and inertia to move in a straight line of the object.

Escape velocity: It is the velocity of an object to overcome or escape the gravitational force of a planet and enter into orbit. Orbital velocity is given as

$${V_{orbital}} = \sqrt {\frac{{G{M_{earth}}}}{r}}$$

Here,

$$G{M_{earth}} = \left( {6.67 \times {{10}^{ – 11}}} \right)\left( {5.9722 \times {{10}^{24}}} \right) = 3.98 \times {10^{14}}\,{m^3}/{s^2}$$

Therefore,

$${V_{orbital}} = \sqrt {\frac{{3.98 \times {{10}^{14}}}}{{6.378 \times {{10}^6}}}} = 7899.494\,m/s = 7.9\,km/s$$

Escape velocity is $\sqrt 2$ orbital velocity,

Therefore,

$${V_{escape}} = \sqrt 2 {V_{orbital}} = \sqrt 2 \times 7899.494\,m/s = 11171.572\,m/s = 11.2\,km/s$$