Suppose that the force of attraction between the sun and the earth is(adsbygoogle = window.adsbygoogle || []).push({});

[tex] F = GMm(\frac{1}{r^2} + \frac{\alpha}{r^3}) [/tex]

Where [tex] \alpha [/tex] is a constant. Show that the orbit does not close on itself but can be described as a precessing ellipse. Find an expression for the rate of precession of the ellipse

First, of all what is a precessing ellipse?

I'm working in polar coordinates [tex] r, \theta [/tex]. Assuming that the sun does not move and is fixed at the orgin of the coordinate system, the equation I get is

[tex] u= \frac{1}{r} = \frac{GMm^2}{L^2}(1+e\cos( A^\frac{1}{2} (\theta - \theta_{0}))) [/tex]

Where [tex] A= (1-\frac{GM \alpha m^2}{L^2}) [/tex]

So how do I show the above parametric equation (if it is correct) describes a precessing ellipse?

**Physics Forums | Science Articles, Homework Help, Discussion**

Dismiss Notice

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Homework Help: Central Forces

**Physics Forums | Science Articles, Homework Help, Discussion**