Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Gravitational Path of an Object

  1. May 17, 2009 #1
    What is the path of an object entering the graviational pull starting at a point [tex][x_{0}, y_{0}, z_{0}][/tex] with a velocity [tex][V_{0x}, V_{0y}, V_{0z}][/tex] neglecting air resistance? This is what I have thus far:

    [tex]x(t)=x_{0}+V_{0x}*t-g_{x}*t^{2}[/tex]
    [tex]y(t)=y_{0}+V_{0y}*t-g_{y}*t^{2}[/tex]
    [tex]z(t)=z_{0}+V_{0z}*t-g_{z}*t^{2}[/tex]

    where
    [tex]g_{x}=\frac{G*M}{r_{x}}[/tex]
    [tex]g_{y}=\frac{G*M}{r_{y}}[/tex]
    [tex]g_{z}=\frac{G*M}{r_{z}}[/tex]

    and the axis projected on the r-axis
    [tex]r_{x}=x*cos\theta*sin\phi[/tex]
    [tex]r_{y}=y*sin\theta*sin\phi[/tex]
    [tex]r_{z}=z*cos\phi[/tex]

    After introducing [tex]\theta[/tex] and [tex]\phi[/tex] the whole thing becomes difficult. Is there an easier way?
     
  2. jcsd
  3. May 17, 2009 #2

    D H

    User Avatar
    Staff Emeritus
    Science Advisor

    NO!

    Philosophaie, based on your other posts, you have a marked tendency to apply equations randomly and incorrectly. Correcting these equations would be a disservice to you because you not understand the theory. Without this understanding, you might use the right equation this time, but you will use the wrong equations again in the future. Please, read a book. Here are three:

    Bate, Mueller, White, "Fundamentals of Astrodynamics". [URL]https://www.amazon.com/Fundamentals-Astrodynamics-Roger-R-Bate/dp/0486600610[/URL][/URL]
    Cost at Amazon: $16.61

    Vallado, "Fundamentals of Astrodynamics and Applications". [URL]https://www.amazon.com/Fundamentals-Astrodynamics-Applications-David-Vallado/dp/1881883140[/URL]
    Cost at Amazon: $63.95.

    Roy, "Orbital Motion". [URL]https://www.amazon.com/Orbital-Motion-3rd-Ed-Roy/dp/0852742290[/URL]
    Cost at Amazon: $70.00.

    Cost of these at a library: Free.
     
    Last edited by a moderator: May 4, 2017
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook




Similar Discussions: Gravitational Path of an Object
Loading...