Physics - Mechanics - Gravitation - Orbital motion and Kepler's laws - Kepler's Laws and Orbital Mechanics

A 5-step lesson. Step 1: 'Kepler's First Law: Planets orbit in ELLIPSES with the Sun at one focus. (Circles are a special case of ellipses.)' Step 2: 'Kepler's Second Law: A line from Sun to planet sweeps out EQUAL AREAS in equal times. Planet moves faster when closer to Sun (perihelion) and slower