A satellite is orbiting in a circular path around the earth close to its surface . What additional velocity is to be imparted to the satellite so that it escapes the earth's gravitational pull ? The radius of the earth= 6400 km and `g=9.8 m*s^(-2)`.

Explanation

Orbital speed of a satellite in an orbit close to the surface of the earth `v=sqrt(gR)`, escape velocity `v_e =sqrt(2gR)`
`therefore` Required additional velocity
`=v_e-v=sqrt(2gR)-sqrt(gR)`
=`(sqrt(2)-1)sqrt(gR) =0.41 xx sqrt(9.8xx6400xx1000)`
`=3.25xx10^3 m*s^(-1)=3.25 km *s^(-1)`.