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Natural Sciences · Intermediate

Gravity & Orbits

Discover that the force pulling an apple down also holds the Moon in its orbit. Fire Newton's cannonball into orbit, uncover Kepler's laws of planetary motion, calculate what it takes to escape Earth entirely, place satellites in useful orbits, and weigh the Earth, Jupiter and the Sun.

7 lessons~35 min0/7 complete
1

Universal Gravitation

One law for apples, moons and planets.

  1. The Inverse-Square LawHow gravity weakens with distance
  2. Weight on Other Worldsg = GM/R²
2

Orbits

Falling around the world.

  1. Newton’s CannonballFast enough to keep missing
  2. Kepler’s LawsEllipses, equal areas, and T² ∝ a³
  3. Escape VelocityLeaving for good
3

Satellites and Scales

Useful orbits, and weighing planets.

  1. Satellite OrbitsLow, medium and geostationary
  2. Weighing WorldsFrom a lab balance to Jupiter

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