Elliptical orbits
This activity belongs to the GeoGebra book Attractive projects.
2D Project: model the terrestrial orbital movement.
We place the point S (Sun) in the center of the coordinates and a point E (Earth) with the initial velocity the vector v. If d is the distance ES, and k is a constant, we have the vector of gravitational force:
- g = k / d² UnitVector(Vector(E, S))
- SetValue(E, E + 0.01 v)
- SetValue(v, v + 0.01 g)
In the following construction we can see a wider version, with the escape velocity and the conservation of mechanical energy.
Note: These two constructions were made thanks to the help of my department colleague Julio Valbuena, who adapted the idea put forward by Richard Feynman in his famous work The Feynman Lectures on Physics (1963, volume I, 9-7, Planetary Movements) .
Author of the construction of GeoGebra: Rafael Losada