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How to calculate the momentum of Pluto?

  1. Dec 18, 2007 #1
    If anyone knows how to calculate the momentum of Pluto it would be great if you could let me know. I am doing a science project and do not understand parts of the project. Thanks!
  2. jcsd
  3. Dec 18, 2007 #2


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    Classical momentum is just mass * velocity

    The orbital radius is around 5.9 billion km, period is 248years so it should be easy to work out velocity.
    The mass is 1.3E22kg
  4. Dec 19, 2007 #3
    Can we know the exact momentum of Pluto at any point in orbit? It's so eccentric.
  5. Dec 19, 2007 #4


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    But rather predictably so.
    Momentum is conserved and a planet has rather a lot of momentum - as you would know if you have ever tried to stop one with your bare hands.
  6. Dec 19, 2007 #5
    I just suspect the momentum of Pluto is not the same around the orbit, it may be quite different. I may have to look back at the Kepler's law.
  7. Dec 19, 2007 #6


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    Angular momentum is more costumary to consider here.

    But for linear momentum:
    mv is consreved, where v is v_radial + v_tangential.
  8. Dec 19, 2007 #7

    D H

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    The linear momentum of a planet (eg. Pluto) is not conserved. The planet follows a curved path!

    Conserved quantities are linear momentum of the planet+sun system (tautologically zero in the planet+sun center of mass frame), angular momentum (gravity is a central force) and total energy (gravity is a conservative force).
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