MadSci Network: Physics

Subject: Solution for motion of two masses under gravity

Date: Sun Dec 19 14:45:33 2004
Posted by Brock
Grade level: grad (science) School: Private Citizen
City: Bogalusa State/Province: Louisiana Country: USA
Area of science: Physics
ID: 1103489133.Ph

I know I found this similar question and answer:
However I would like to know the exact equation / function that describes the
motion of the two masses.

Two masses M1 and M2 are released at rest in a vacuum, and the only force acting
on them is their own gravity. Using only F=ma and F=Gm1m2/r^2 solve for the
function x1=f1(t) and x2=f2(t) ... position of mass 1, x1, as a function, f1, of
time, and position of mass 2, x2, as a function, f2, of time.

I start out with: F=m1a2, F=m2a2, F=Gm1m2/(x2-x1)^2 ... Then notice that
a1=v1'=x1" and a2=v2'=x2" ... so you get a set of differential equations:

x1"(x2-x1)^2=Gm2 and x2"(x2-x1)^2=Gm1
But I don't know where to go from there, mathematically.


Re: Solution for motion of two masses under gravity

Current Queue | Current Queue for Physics | Physics archives

Try the links in the MadSci Library for more information on Physics.

MadSci Home | Information | Search | Random Knowledge Generator | MadSci Archives | Mad Library | MAD Labs | MAD FAQs | Ask a ? | Join Us! | Help Support MadSci

MadSci Network,
© 1995-2004. All rights reserved.