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Homework Help: Does anyone can answer my questions?

  1. Sep 28, 2007 #1
    if a planet revolves around a star in an ellipticle orbit and the position of star changes from one focus of ellipse to another then what happens to the angular velocity of planet(direction, sense of revolution )
  2. jcsd
  3. Sep 28, 2007 #2


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    Is the change instantaneous or over a period of time?

    Switching the stars mass from one focus to the other would certainly change the orbital dynamics, depending on when the change occurred.

    The direction of revolution would not change, but the dynamics have to change, e.g. if the planet was in periapsis (or perihelion) and the star was moved to the other focus (toward apoapsis), then the planet would necessarily do what? Similarly, what if the planet was at apoapsis and the star move to the other focus?
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