Gravitational Path of an Object

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SUMMARY

The discussion focuses on the gravitational path of an object entering a gravitational field from an initial position [x_{0}, y_{0}, z_{0}] with a velocity [V_{0x}, V_{0y}, V_{0z}], neglecting air resistance. The equations provided for the object's trajectory are x(t)=x_{0}+V_{0x}*t-g_{x}*t^{2}, y(t)=y_{0}+V_{0y}*t-g_{y}*t^{2}, and z(t)=z_{0}+V_{0z}*t-g_{z}*t^{2}, where g_{x}, g_{y}, and g_{z} are derived from gravitational force equations. A participant emphasizes the need for a solid theoretical understanding of astrodynamics, recommending foundational texts such as "Fundamentals of Astrodynamics" by Bate, Mueller, and White, and others to correct misconceptions and improve comprehension.

PREREQUISITES
  • Understanding of gravitational force equations
  • Familiarity with basic kinematics
  • Knowledge of spherical coordinates and their applications
  • Basic calculus for understanding motion equations
NEXT STEPS
  • Study "Fundamentals of Astrodynamics" by Bate, Mueller, and White
  • Explore "Fundamentals of Astrodynamics and Applications" by Vallado
  • Read "Orbital Motion" by Roy for advanced concepts
  • Practice deriving gravitational equations in spherical coordinates
USEFUL FOR

Aerospace engineers, physics students, and anyone interested in understanding the dynamics of objects in gravitational fields will benefit from this discussion.

Philosophaie
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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?
 
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Philosophaie said:
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]

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/dp/0486600610/?tag=pfamazon01-20[/URL][/URL]
Cost at Amazon: $16.61

Vallado, "Fundamentals of Astrodynamics and Applications". [URL]https://www.amazon.com/dp/1881883140/?tag=pfamazon01-20[/URL]
Cost at Amazon: $63.95.

Roy, "Orbital Motion". [URL]https://www.amazon.com/dp/0852742290/?tag=pfamazon01-20[/URL]
Cost at Amazon: $70.00.

Cost of these at a library: Free.
 
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