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Homework Help: Satellite orbit equation

  1. Sep 22, 2010 #1
    1. The problem statement, all variables and given/known data

    The problem is that a satellite is ejected from a planet radius R and mass M, that has no atmosphere, 30 degrees from vertial with velocity vo.

    This is a multi part problem dealing with center of mass/inertia, the part I need help with is the following:

    1. When the satellite is at point B, what is the velocity in terms of point A?

    Point A is R away from the center of the planet (so it is on the surface of the planet) and Point B is 3R from the center of the planet.

    2. What is equation to relate vo to R?

    2. Relevant equations

    conservation of E and angular momentum

    3. The attempt at a solution

    For 2, I am very lost.

    For 1:
    I did

    KEi + PEi = KEf +PEf

    (1/2)*m(satellite)*vo^2 - G*m(earth)*m(satellite)/R= (1/2)*m(satellite)*vb^2 - G*m(earth)*m(satellite)/3R

    this simplifies to Vb^2=Vo^2 - 16/9 * G*m*(earth)/R
    Last edited: Sep 22, 2010
  2. jcsd
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