Physics Laws & Theorems
Intermediate

First Law of Thermodynamics

Change in internal energy equals heat added minus work done.

Formula

ΔU=Q−W\Delta U = Q - W

Variables

\Delta UInternal energy
QHeat
WWork

Example

Energy accounting for systems

Did You Know?

The first law of thermodynamics is simply energy conservation applied to heat, dooming all perpetual-motion machines.

thermodynamicslaw