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Homework Help: Could you calculate the mass of the planet?

  1. Dec 3, 2006 #1
    1. If you know the distance to a planet and the centripetal force on it, could you calculate the mass of the planet? Explain.

    Fc = (MV^2) / (R)

    I don't even know where to start; in the equation above, you can only substitute the known centripetal force in, but you can't substitute the distance to a planet or the velocity in.. Is there another equation or expression for centripetal force that would satisfy the two variables in the prompt?
  2. jcsd
  3. Dec 3, 2006 #2


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    Homework Helper

    Hint: if you assume the planet is rotating around another one (which you can, since there exists a centripetal force), which is the other force which comes to your mind? (Hint 2: Newton's law of ___________)
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