Astrophysics - calculating orbital period

[superdave]

1. The problem statement, all variables and given/known data
Show that a satellite in low-Earth orbit is approximately P = C(1 + 3h/2R_E) where h is the height of the satellite, C is a constant, and R_E is the radius of the earth)

2. Relevant equations

Unsure

3. The attempt at a solution

I have no idea how to approach this.

[tiny-tim]

hi superdave! :smile:

(try using the X2 icon just above the Reply box :wink:)

use centripetal acceleration and Newton's gravtiational law …

what do you get? :smile:

[superdave]

a= GM/r2 =v2/r

v2=GM/r

Aaand, I'm stuck again.

[tiny-tim]

hi superdave! :smile:

(just got up :zzz: …)

hint: you need P, so write the centripetal acceleration as ω2r instead of v2/r :wink:

(and then compare r with r+h)