1. Not finding help here? Sign up for a free 30min tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Apogee and perigee

  1. Jan 11, 2005 #1
    i know the equation for both, apogee=a(1+e) perigee=a(1-e). i know the e stands for eccentricity, but what does the a stand for? thanks.
  2. jcsd
  3. Jan 11, 2005 #2


    User Avatar
    Science Advisor
    Homework Helper

    Since the sum of the apogee and the perigee will give you the length of the major axis of the ellipse, consider a(1+e)+a(1-e)=2a.
    So a is the length of the semi-major axis of the ellipse.

    It's the same 'a' as in the equation for an ellipse:

    (if b<a).
  4. Jan 11, 2005 #3
    thank you.
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?

Similar Discussions: Apogee and perigee
  1. Moon apogee (Replies: 1)