The JAVA applet illustrates the effects of HEAT and WORK on an ideal monatomic gas in a cylinder with a frictionless piston. Select Isochoric (constant volume), Constant, Increase, or Decrease from the "External Pressure" menu and Adiabatic, Add, Remove, or Isothermal (constant temperature) from the "Heat" menu. In an adiabatic process the ideal gas (the thermodynamic system) is isolated from the surroundings and no heat is gained or lost by the ideal gas. Click the "Start" button to begin the animation. It takes several seconds for the system to equilibrate. The appearance of the mean square velocity below the bottom of the cylinder marks the beginning of the process. Allow the animation to run for another forty-five seconds and then click the "Stop" button. The initial and final pressures, temperatures, and volumes will be displayed above the piston. If the process involves a volume change, the animation will stop automatically.

    Use the applet to perform the following experiments and answer the questions. See the Tutorial for Experiment: Heat and Pressure-Volume Work for an example and help.

1. Select Isochoric from the "External Pressure" menu and Adiabatic from the "Heat" menu. Click the "Start" button and allow the animation to run for 45 seconds after the appearance of the mean square velocity. Describe the mean square velocity of the 30 gaseous atoms during the process. Stop the animation and record the initial and final pressures, temperatures and volumes. Calculate DP = P_final - P_initial , DT =T_final - T_initial , and DV = V_final - V_initial .
2. Select Isochoric from the "External Pressure" menu and Add from the "Heat" menu. Click the "Start" button and allow the animation to run for 45 seconds after the appearance of the mean square velocity. Describe the mean square velocity during the process. How do the differences between the initial and final pressures ( DP), temperatures ( DT), and volumes ( DV) in this process compare with DP, DT, and DV in the previous process (#1)? Why is DP, DT,or DV for the two processes not the same?
3. Select Constant from the "External Pressure" menu and Remove from the "Heat" menu. Click the "Start" button and allow the animation to run for 45 seconds after the appearance of the mean square velocity. Describe the mean square velocity during the process. Why do temperature and volume change in this process?
4. Select Increase from the "External Pressure" menu and Adiabatic from the "Heat" menu. Click the "Start" button and allow the animation to run for 45 seconds after the appearance of the mean square velocity. Describe the mean square velocity during the process. Why is there a change in the temperature, if this process is adiabatic?
5. Select Increase from the "External Pressure" menu and Isothermal from the "Heat" menu. Click the "Start" button and allow the animation to run for 45 seconds after the appearance of the mean square velocity. Describe the mean square velocity during the process. Why is DT for this process different from DT for the previous process (#4)?

    Include data from your experiments to support your answers to the questions.

    If you have preformed all of the experiments, answered all of the questions, and completed the report to be submitted for credit, then you may check the Answers to Heat and Pressure-Volume Work Questions