Newton's Law of gravitation using kepler's laws.

1. Sep 23, 2007

Sourabh N

1. The problem statement, all variables and given/known data

Derive Newton's Law of gravitation using kepler's laws.

2. Relevant equations

Kepler's law equations.
etc.

3. The attempt at a solution

l= r(1- e*cos(theta)) l- const. e- eccentricity
Solving these equations using kepler's laws (r^2(d(theta)/dt), etc.)

second time derivative of r = -4c^2/(lr^2) + 4c^2/r^3
subtracting centrifugal acc. (4c^2/r^3) from it I get Newton's law.

But I don't know how the centrifugal acc. come here.

2. Sep 23, 2007