Lesson

• Gravity Lesson (Slides) — 12-slide deck covering F = m·a, gravity, and Newton's Law of Universal Gravitation
• Gravity Lesson (PDF)

Interactive Simulations

• Falling Ball — watch a ball fall under gravity and see F = m·a in action
• Gravity Playground — create and launch objects in a free-form gravity sandbox
• Ground Gravity Lab — experiment with dropping objects of different masses

Source Code

• gravity.js — the falling-ball physics code
• ground-gravity.js — drop a ball on different planets and compare