Interactive Self-Study Module: First Law - Closed Systems

This module uses screencasts and interactive simulations to explain the first law of thermodynamics for a closed system, which means no mass flows into or out of the system. In the examples and simulations, the pistons are assumed to be frictionless. Most of the calculations use absolute temperature except when calculating a temperature difference since that is the same for K or °C. The module provides example problems to allow the user to test themselves. We suggest using the learning resources in the following order:

    1. Attempt to answer the multiple choice ConcepTests before watching the screencasts or working with the simulations.
    2. Watch the screencast that provides an introduction to energy balances and answer the questions within the screencast.
    3. Use the interactive simulation to further understand the the first law for closed systems.
    4. Try to solve the two example problems before watching the solutions in the screencasts.
    5. Answer the ConcepTests.

     Understanding how to perform an energy balance on a closed system will better facilitate understanding energy and balances on open systems. 

               This module is intended for a thermodynamics course.


    • Be able to apply the ideal gas law.
    • Know how to calculate energy changes for an ideal gas.

    After studying this module, you should be able to:
    1. Perform energy balances around a closed system.
    2. Determine final states of various processes (e.g., constant pressure, adiabatic,constant volume, and constant temperature).