Angular Momentum

Mechanics · 1775

Equation: L = r × p = Iω; dL/dt = τ
Field: Mechanics
Symbols: L angular momentum · r position from the axis · p linear momentum · I moment of inertia · ω angular velocity · τ net torque
Year: 1775

Significance

What a spinning or orbiting body keeps unless a torque acts on it. Kepler's second law — equal areas in equal times — is its conservation for a planet, seen eighty years before Newton explained why. It is why a gyroscope holds its axis, why a collapsing star spins up into a pulsar, and why a turbine's blades are shaped to change the working fluid's angular momentum as it passes.

Machines

Steam Turbine Gas Turbine (Jet Engine)Pelton Wheel Francis Turbine Kaplan Turbine

Requires

Cross Product Moment of Inertia Momentum and Impulse

Required By

Kepler's Second Law Slide to Roll Kepler's First Law

Referenced by

equation

Cross Product Kepler's First Law Kepler's Second Law Moment of Inertia Momentum and Impulse Slide to Roll

machine

Francis Turbine Gas Turbine (Jet Engine)Kaplan Turbine Pelton Wheel Steam Turbine

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From the Equations database in Notion, last edited 2026-08-18. This page is the row, rendered by the build; nothing on it is written by hand.