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Homework Help: Asteroids and their total energy

  1. Jun 19, 2013 #1
    http://s9.postimg.org/vejo37agv/physics.jpg [Broken] for picture

    Asteroids X, Y, Z have equal mass (6kg each). They orbit around a planet with M=6×1024kg. The orbits are in the plane of the paper and are drawn to scale.

    TE, KE and PE represent Total, Kinetic and Potential energies.
    Select G-Greater than, L-Less than, or E-Equal to. (If the first is G and the rest L, enter GLLLLLL).

    A) The KE of Y at 7 is .... its value at 5.
    B) The speed of X at 6 is .... it is at 5.
    C) The PE of X at 5 is .... the PE of Y at 5.
    D) The PE of X at 5 is .... the PE of Y at 7.
    E) The TE of Z is .... the TE of X.
    F) The TE of Y is .... the TE of Z.
    G) The PE of X at 5 is .... its value at 3.

    Hello, guys I've attempted this many times. My most certain answer is ELEELGl. I was wondering if anyone could help me with this. I am pressure sure A B C D G are correct. But i am not sure about E and F. I've tried ELEEGLl and ELEEEEl also. Those don't work either.

    The unit is on conservation of energy.
    Last edited by a moderator: May 6, 2017
  2. jcsd
  3. Jun 19, 2013 #2

    Andrew Mason

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    Homework Helper

    How is the total energy related to: 1. the length of the semi-major axis of the elliptical orbit or 2. the radius of a circular orbit? Is the semi-major axis of Z greater or less than the radius of Y? You may have to measure this to find out.

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