Formula: First Law of Thermodynamics Internal energy    Thermal energy    Work

Formula: First Law of Thermodynamics
Change in the Internal Energy of a System

Internal energy

Change of internal energy \(\Delta U=U_2-U_1 \) of a system (e.g. a gas) is the sum of the amount of heat \(Q\) and the work \(W\) done.

Thermal energy

Thermal energy (heat) added to the system (\(\class{orange}{\Delta Q}>0\)) or released from the system (\( \class{orange}{\Delta Q}< 0 \)).


Work done ON the system (\( \class{purple}{\Delta W} > 0\)) or work done BY the system (\(\class{purple}{\Delta W} < 0\)).

+ Perfect for high school and undergraduate physics students
+ Contains over 500 illustrated formulas on just 140 pages
+ Contains tables with examples and measured constants
+ Easy for everyone because without vectors and integrals

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