A fixed mass of an ideal gas is initially at a temperature of 
. The gas has a volume of 
and a pressure of 
. The gas undergoes three successive changes, as shown in the figure below.
The initial state is represented by point A. The gas is cooled at constant pressure to point B by the removal of 
of thermal energy. The gas is then heated at constant volume to point C. Finally, the gas expands at constant temperature back to its original pressure and volume at point A. During this expansion, the gas does 
of work.
Show that the magnitude of the work done during the change AB is 
.
Complete the table below to show the work done on the gas, the thermal energy supplied to the gas and the increase in internal energy of the gas, for each of the changes AB, BC and CA.
