Calculate the minimum velocity required by spacecraft to escape the earth's gravitational forces.

Explanation

(i) Space launch vehicles are used for the lauching artifical satellites which overcome the earth gravitational force and move into space.
(ii) The velocity of an object should be more than the ecapse velocity , only then the object can be lauched into space.
`V_(esc) = sqrt((2GM)/(R))`
G - Gravitational constant ` = 6.67 xx 10^(-11) Nm^(2)// kg^(2)`
M - Mass of the planet (earth ) ` = 6 xx 10^(24) kg`
R -Radius of the earth ` = 6.4xx 10^(6)` m
` therefore V = sqrt((2GM)/( R))`
` V = sqrt(( 2 xx 6.67 xx 10^(-11) xx 6 x 10^(24))/(6.4 xx 10^(6))`
` v = 11.18 xx 10^(3) m//s = 11.18 km//s`
Hence , the escape velocity for earth is `11.18 km//s` .
The satellite launch should have velocity more than or at least `11.2 km//s`