Angular Velocity of a satellite

[notsam]

Homework Statement

A satellite moves in a circular orbit around
the Earth at a speed of 6.6 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.

Homework Equations

m= mass of the satalite, M= mass of eart, G=gravitational constant, v= veolocity, r= radius of the entire orbit, and re= radius of the earth

The Attempt at a Solution

Ok so I start with GmM/r^2=mv^2/r, and then I simplify to r= GM/v^2, solving for r I get 916025899 km I then subtract the radius of the Earth "re" from it to get, 9160252629 km. This however is not the correct awnser. I can't figure what I am doing wrong I have already converted all of my units to km. I would REALLY REALLY appreciate step by step instructions on what I am doing wrong.

 

[Doc Al]

Ok so I start with GmM/r^2=mv^2/r, and then I simplify to r= GM/v^2, solving for r I get 916025899 km

Did you use correct units? That equation assumes standard units: v in m/s, r in meters, etc.

Use standard units, then convert to whatever you want at the end.

 

[notsam]

You're a genius, I could'nt figure out what I was doing wrong thank you.