Initially, 0.05 kg of air is contained in a piston–cylinder device at 200° C and 1.6MPa. The air then expands at constant temperature to a pressure of 0.4 MPa. Assume the process occurs slowly enough that the acceleration of the piston can be neglected. The ambient pressure is 101.35 kPa.

A. Determine the work (kJ) performed by the air in the cylinder on the piston.

B. Determine the work (kJ) performed by the piston on the ambient environment. Neglect the cross-sectional area of the connecting rod.

C. Determine the work transfer (kJ) from the piston to the connecting rod. Neglect friction between the piston and cylinder. Assume that no heat transfer to or from the piston occurs and that the energy of the piston does not change.

D. Discuss why the assumption of negligible piston acceleration was made.

E. Which of these work interactions might be useful for driving a car? Why?

Transcribed Image Text:

State 1 T=Constant State 2