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Homework Help: Gravitational Accelaration

  1. Mar 2, 2006 #1
    If an object were discovered oriting at a radius of 3*10^6 m, what would be the time that it would take to complete one orbit around the sun?
    So I know I need to use the following equation:

    T^2/R^3 = 4pie^2/GM

    but do I use the radius they gave me or do I have to add that radius to the the radius of the sun to get R?
  2. jcsd
  3. Mar 2, 2006 #2
    check your radius .... it seems to be smaller then the radius of the sun!!
  4. Mar 2, 2006 #3

    Chi Meson

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    The radius in the formula is the radius of the circle of the orbit. However, the Sun's radius is quite a bit more than 3 million meters (The Earth's radius is 6 million meters)!

    If this is exactly how the question is stated, the the question is flawed. Perhaps the problem was intended to be 3 million meters above the surface of the sun. In that case you would add 3*10^6 to the Sun's radius of 6.96*10^8 meters, which would be 6.99*10^8 meters. This is almost insignificant, but it would be my assumption as to what the intent of the question was.
    Last edited: Mar 2, 2006
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