A2L Item 190

Goal: Hone the concept of work for a thermodynamic system

Source: UMPERG-ctqpe190

An
ideal gas is taken around the process shown. The net work done
on the gas is most nearly…

  1. 20 J
  2. -30 J
  3. 15 J
  4. -10 J
  5. none of the above
  6. cannot be determined

Commentary:

Answer

(4) The work done ON the system is the negative of the area of
the triangle. Students selecting answer #1 or #3 need to be sensitized
to the difference between work done on the gas versus by the gas.