Question

An artificial satellite is in an elliptical orbit around the earth with aphelion of `6R` and perihelion of `2R` where `R` is radius of the earth `=6400km`. Calculate the eccentricity of the elliptical orbit.

Answer 1

We know that,
perigee `(r_(p))=a(1-e)=2R`.....(1)
apogee `(r_(a))=a(1+e)=6R`.....(2)
Solving (1) & (2), eccentricity `(e)=0.5`