Calculate Satellite Velocity at 3600 km Above Earth

[pb23me]

1. Homework Statement [/b]
calculate the velocity of a satellite 3600 km above the surface of the earth.

Homework Equations

Fnet= mg=ma
mg=ma
g=V²/r
r=3600000

The Attempt at a Solution

5940 m/s I am pretty sure this is correct just want to make sure.

 

[Xerxes1986]

Looks good to me as long as you plugged in all the right values

 

[Filip Larsen]

Two things you need to include in your calculation:
1) at 3600 km above the surface of Earth, the acceleration due to gravity is not same as at the surface.
2) The radius in the circular motion equation is not 3600 km.
The correct value is a bit more than what you got.

 

[Xerxes1986]

Two things you need to include in your calculation:
1) at 3600 km above the surface of Earth, the acceleration due to gravity is not same as at the surface.
2) The radius in the circular motion equation is not 3600 km.
The correct value is a bit more than what you got.

You are right...but the equations are right, and as we all know that is all that matters once you start grad school :P haha

 

[gau_physics]

Just equate centripetal acceleration to the gravitational force at that height.
Better just remember the formula instead of deriving each time -

v = sq root (GM/r)

where G = grav constant, M= mass of earth, r = distance from centre of earth