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Speed of Satellite at Perigee and Apogee

  1. Nov 16, 2009 #1
    1. The problem statement, all variables and given/known data
    2ege0d5.jpg

    2. Relevant equations
    g=GMm/r^2
    e=c/a
    g=v^2/r

    3. The attempt at a solution

    a) v^2/r=GM/r^2 m<<M
    v^2=GM/r
    v=SGRT(GM/r)

    I don't think this is valid though since the orbit is not circular. I don't know how to alter the equation so it also applies to the elliptical orbit of the problem.

    Thanks so much for any help.
     
  2. jcsd
  3. Nov 16, 2009 #2

    Andrew Mason

    User Avatar
    Science Advisor
    Homework Helper

    There are two things that are conserved: angular momentum and energy. Try writing out the equation for the conservation of energy and the equation for the conservation of angular momentum and see if you can solve for the velocity at the apogee.

    AM
     
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