A satellite moves in a circular orbit around

the Earth at a speed of 5.3 km/s.
Determine the satellite’s altitude above
the surface of the Earth. Assume the
Earth is a homogeneous sphere of radius
6370 km and mass 5.98 × 1024 kg. The
value of the universal gravitational constant
is 6.67259 × 10−11 N · m2
/kg2
.
Answer in units of km

1 answer

you know that

v^2 = GM^2 / (M+m)r

You have (or can easily calculate) G,M,m and r.

Plug and chug. Note that for m<<M, the approximate relation is

v^2 = GM/r