Classical Mechanics | 7.2: Universal Gravitation and the Principle of Equivalence

Full course — free exercises, Feynman reviews, and AI-graded feedback: https://ludium.ai/courses/classical-m... Push on why a spring pulls back and the answer keeps retreating, into the metal, its atoms, and the charges that bind them. To truly explain any force, physics hunts for a small set of fundamental forces, and this video meets the first: gravity. Key concepts covered: Newton's Universal Law of Gravitation and its inverse-square falloff The gravitational constant G and the direction of the force Gravitational mass versus inertial mass, and the Principle of Equivalence Near-surface gravity: why the force is nearly constant and equal to mass times g How g varies with latitude and elevation through Helmert's equation ━━━━━━━━━━━━━━━━━━━━━━━━ SOURCE MATERIALS The source materials for this video are from https://ocw.mit.edu/courses/8-01sc-cl...