A sealed cylinder contains an ideal gas that is taken from state A to state B along the straight–line path shown in the following verbal description of a pressure–volume plot:
• State A: pressure PA=150kPa, volume VA=0.30m3
• State B: pressure PB=60kPa, volume VB=0.90m3
The line connecting A to B on the P–V graph is linear.
During the process the internal energy of the gas decreases by 32kJ.
(1) Estimate the work done on the gas as it moves from A to B by calculating the area under the straight-line path. Provide the sign of the work and justify your estimation method.
(2) Using the value of work from part (a) and the stated change in internal energy, determine the energy transferred by heating Q. Give the sign and magnitude.
(3) Explain, without additional calculation, whether the magnitude of the temperature at state B is greater than, less than, or equal to that at state A. Support your answer with appropriate reasoning.