Equations · equation

First Law of Thermodynamics

Thermodynamics · 1850

Equation: ΔU = Q − W
Field: Thermodynamics
Named After: Julius Robert von Mayer · James Joule · Rudolf Clausius
Symbols: ΔU change in internal energy · Q heat added to the system · W work done by the system
Year: 1850

Significance

Energy is never created or destroyed, only moved and converted — heat in, work out, the books always balance. The law that retired the perpetual-motion machine.

Theories

Machines

Newcomen Atmospheric Engine Watt Steam Engine

Related

Joule Heating Bernoulli's Equation Noether's Theorem Cosmological Fluid Equation

Requires

Required By

Thermal Efficiency Coefficient of Performance Adiabatic Relation Cosmological Fluid Equation Gibbs Free Energy

Referenced by

equation

Adiabatic Relation Bernoulli's Equation Coefficient of Performance Cosmological Fluid Equation Gibbs Free Energy Joule Heating Noether's Theorem Thermal Efficiency Work

machine

Newcomen Atmospheric Engine Watt Steam Engine

theory

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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.