## Problem 21.5: Engine cycle and PV diagram

A mass is pushed downward on top of a container (the dimension of the container into the computer screen is 30 cm) filled with an ideal monatomic gas that undergoes a thermodynamic process as shown in the animation (pressure is given in atmospheres, position is given in centimeters, temperature is given in degrees Celsius, and time is given in seconds). Both the dial and the relative height of the black box on the piston represent the changing pressure. Restart.

1. Determine how many moles of gas are in the container.
2. Find the following:
• The work done by or on the gas in each step.
• The heat gained or lost by the gas in each step.
3. Draw a PV diagram for this engine cycle.
4. Calculate the efficiency of this engine.

Problem authored by Anne J. Cox.
Script authored by Mario Belloni and Anne J. Cox.

Physlets were developed at Davidson College and converted from Java to JavaScript using the SwingJS system developed at St. Olaf College.