Motion, force, and the geometry of cause.
Classical Mechanics
Classical mechanics describes how matter moves under forces — from a falling apple to orbiting moons. It's the language of Newton's laws, energy, and momentum.
Chapter outline
Lessons in this chapter
Short, focused lessons. Each one ends with a worked example and a quick quiz.
Key concepts at a glance
The essential ideas, paired with their equations.
Newton's Second Law
01Net force equals mass times acceleration — the cornerstone of dynamics.
Conservation of Energy
02Total mechanical energy is conserved in a closed system without friction.
Momentum
03A measure of an object's motion; conserved when no external force acts.
Universal Gravitation
04Every mass attracts every other mass — the force that orbits planets.
Work–Energy Theorem
05The work done on an object equals its change in kinetic energy.
Rotational Motion
06Torque produces angular acceleration scaled by moment of inertia.
Frequently asked
What is classical mechanics?+
Classical mechanics is the branch of physics describing the motion of macroscopic objects under forces, formalized by Newton's three laws.
Why does F = ma matter?+
It links cause (force) with effect (acceleration), letting us predict motion from interactions.