Summary

‣ This section covers key concepts encountered during your study of thermodynamics. It provides an overview of important principles and sign conventions that will help you in understanding how energy, heat, and work interact in thermodynamic systems.

Key Concepts

Work is defined as energy transfer through means other than heat, measured in joules (J).
The first law of thermodynamics: ΔU = Q − W, where:
- ΔU = Internal energy change
- Q = Net heat transfer
- W = Net work done
Internal energy remains constant (ΔU = 0) when work done equals heat transfer (W = Q).
Heat addition increases internal energy, while heat removal decreases it.
Thermal energy corresponds to molecular kinetic energy in random motion.
Temperature changes reflect average molecular kinetic energy variations.
Energy conservation: Transformable between forms but never created/destroyed.

Thermodynamic Sign Convention

Q > 0: Heat input to system
Q < 0: Heat output from system
W > 0: Work performed by system
W < 0: Work applied to system
ΔU > 0: System energy increase
ΔU < 0: System energy decrease
ΔU = 0: Energy equilibrium state

Learning is a continuous journey. Keep exploring, practicing, and deepening your understanding of thermodynamics. The concepts covered here are just the beginning of your studies in this fascinating field!