Derive equation of trajectory of a body around a fixed body attracted by gravity

AI Thread Summary
The discussion focuses on deriving the trajectory equation for a body of mass m orbiting a fixed mass M under gravitational attraction. The trajectory can be an ellipse, parabola, or hyperbola, depending on initial conditions like velocity and mass ratios. Participants mention using Newton's Law of Gravity and polar coordinates to solve the problem, noting that the calculations can be complex and lengthy. A request for resources on solving the Kepler problem is made, highlighting the need for guidance in navigating the intricate mathematics involved. The conversation emphasizes the relationship between initial conditions and the resulting orbital shape.
gupta.shantan
Messages
2
Reaction score
0

Homework Statement



There is a fixed spherical body of mass M whose center is to be taken as origin. Another body of mass m whose initial position vector \vec{r} is given. This body is projected with initial velocity \vec{v}. Find the equation of trajectory of body with mass m around the body with mass M.

Homework Equations



Will the trajectory be an ellipse, just like the orbit of Earth around the sun?

The Attempt at a Solution



I tried solving the position using Newton's Law of Gravity. I also tried using the formula a = v dv/dx and integrating but was unable to reach a solution.

Any help is greatly appreciated...
 
Physics news on Phys.org
Your problem is known as Kepler problem.

It is possible to derive the trajectory with Newton's Law of gravity, but this is an ugly calculation, at least ~2 pages long, involving polar coordinates, some substitutions and messy integrals.

Depending on the velocity, the radius and the masses M and m, the trajectory can be:
- an ellipse
- a parabola
- a hyperpola
which are all conic sections
 
thank you mfb
but i am willing to go through the messy mathematics. So can u please help me by giving me a link to where this Kepler problem has been solved.
 
Thread 'Collision of a bullet on a rod-string system: query'
In this question, I have a question. I am NOT trying to solve it, but it is just a conceptual question. Consider the point on the rod, which connects the string and the rod. My question: just before and after the collision, is ANGULAR momentum CONSERVED about this point? Lets call the point which connects the string and rod as P. Why am I asking this? : it is clear from the scenario that the point of concern, which connects the string and the rod, moves in a circular path due to the string...
Back
Top