As you have learnt in the text, a geostationary satellite orbits the earth at a height of nearly 36,000 km from the surface of the earth. What is the potential due to earth’s gravity at the site of this satellite ? (Take the potential energy at infinity to be zero). Mass of the earth `= 6.0Xx10^24 kg`, radius = 6400 km.

Explanation

We are given: `h= 36000km and R= 6400km`
Distance of satellite from the centre of earth `=R+h=6400+36000=42400km=4.24 xx 10^(7)m`
We are to calculate: Gravitational potential at a height R+h.
Using the relation: `V= -(GM)/(r )`. Here `r = R+h`
`V= (6.67 xx 10^(-11) xx 6.0 xx 10^(24))/(4.24 xx 10^(7))= -9.44 xx 10^(6)J//kg`