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Homework Help: Orbiting satellites

  1. Jun 27, 2007 #1
    1. The problem statement, all variables and given/known data
    why a more massive communications satellite doesn't orbit more slowly than a smaller one?

    2. Relevant equations

    3. The attempt at a solution

    The larger satellite will have more mass but it will also have a far greater gravitational force acting on it no matter where it is orbiting. These two will cancel each out. So they will freefall at the same rate providing it is the same distance from the planet.
  2. jcsd
  3. Jul 1, 2007 #2


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    Staff Emeritus
    Science Advisor

    Things to think about:
    1. What type of orbit does communications satellites orbit the earth in?
    2. What force provides the acceleration for this orbit?
    3. This force is the centripetal force, which can be written down for an object in circular motion.
    4. Equating these two expressions should tell you the answer to your question.
  4. Jul 2, 2007 #3


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    Science Advisor
    Gold Member

    Consider Kepler's law and what role the satellite mass plays in determing the orbital period.
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