# 7: Conservation of Energy

$$\newcommand{\vecs}[1]{\overset { \scriptstyle \rightharpoonup} {\mathbf{#1}} }$$ $$\newcommand{\vecd}[1]{\overset{-\!-\!\rightharpoonup}{\vphantom{a}\smash {#1}}}$$$$\newcommand{\id}{\mathrm{id}}$$ $$\newcommand{\Span}{\mathrm{span}}$$ $$\newcommand{\kernel}{\mathrm{null}\,}$$ $$\newcommand{\range}{\mathrm{range}\,}$$ $$\newcommand{\RealPart}{\mathrm{Re}}$$ $$\newcommand{\ImaginaryPart}{\mathrm{Im}}$$ $$\newcommand{\Argument}{\mathrm{Arg}}$$ $$\newcommand{\norm}[1]{\| #1 \|}$$ $$\newcommand{\inner}[2]{\langle #1, #2 \rangle}$$ $$\newcommand{\Span}{\mathrm{span}}$$ $$\newcommand{\id}{\mathrm{id}}$$ $$\newcommand{\Span}{\mathrm{span}}$$ $$\newcommand{\kernel}{\mathrm{null}\,}$$ $$\newcommand{\range}{\mathrm{range}\,}$$ $$\newcommand{\RealPart}{\mathrm{Re}}$$ $$\newcommand{\ImaginaryPart}{\mathrm{Im}}$$ $$\newcommand{\Argument}{\mathrm{Arg}}$$ $$\newcommand{\norm}[1]{\| #1 \|}$$ $$\newcommand{\inner}[2]{\langle #1, #2 \rangle}$$ $$\newcommand{\Span}{\mathrm{span}}$$$$\newcommand{\AA}{\unicode[.8,0]{x212B}}$$

• 7.1: Mechanics and the Mechanical Energy Balance
Defining mechanical work and power, the work-energy principle, and the mechanical energy balance. Discussion of springs as a source of mechanical energy.
• 7.2: Four Questions
Four questions needed to develop an accounting concept for the property of energy: What is energy? How can it be stored in a system? How can it be created or destroyed? How can it be transported? Conservation of energy and the work-energy principle.
• 7.3: Conservation of Energy
Application of the conservation of energy principle to systems. Standard assumptions made about heat transfer and work in such applications. Includes multiple worked examples.
• 7.4: Substance Models
Equations of state for two simple substance models: the ideal gas model with room-temperature specific heats and incompressible substance model with room-temperature specific heats. Includes several worked examples.
• 7.5: Flow Work and Flow Power Revisited
More detailed explanation of flow work and flow power, in the case of systems with mass flow in/out and cases with multiple inlets/outlets.
• 7.6: Work and Power Revisited
Introduction to the concept of transferring energy through quasiequilibrium vs non-quasiequilibrium work.
• 7.7: Heat Transfer Revisited
Key concepts of heat transfer, including heat flux and the physical mechanisms (conduction, convection, and thermal radiation) by which heat transfer occurs.
• 7.8: Electrical Energy Storage and Transfer
Instantaneous and average electrical power, for DC systems. Average electrical power for steady-state AC systems. Storage of electrical energy in resistors, capacitors, inductors, and batteries.
• 7.9: Thermodynamic Cycles
Definition and classification of thermodynamic cycles. Discussion of power cycles, refrigeration cycles, and heat pumps, as well as their measures of performance.
• 7.10: Problems

This page titled 7: Conservation of Energy is shared under a CC BY-NC-SA 4.0 license and was authored, remixed, and/or curated by Donald E. Richards (Rose-Hulman Scholar) via source content that was edited to the style and standards of the LibreTexts platform; a detailed edit history is available upon request.