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) a turtle-example-suite:
tdemo_planets_and_moon.py
Gravitational system simulation using the
approximation method from Feynman-lectures,
p.9-8, using turtlegraphics.
Example: heavy central body, light planet,
very light moon!
Planet has a circular orbit, moon a stable
orbit around the planet.
You can hold the movement temporarily by
pressing the left mouse button with the
mouse over the scrollbar of the canvas.
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