Which of the following is an example of a reliable source?
A. A pamphlet on the economics of bridge building published by the organization
Citizens Against Government Spending.
B. An article in Environmental Science and Technology, a peer-reviewed journal
published by the American Chemical Society.
C. A newspaper editorial written by a United States senator.
D. A blog post by a university engineering student.

Air inially occupying a volume of 1 m2 at 100 kpa, 27 c undergoes three internally reversible processes in series. process 1-2 compression to 500 kpa during which pv constant process 2-3 adiabatic expanslon to 100 kpa process 3-1: constant-pressure expansion to 100 kpa (a) calculate the change of entropy for each of the three processes. (b) calculate the heat and work involved in each process. (c) is this cycle a power cycle or refrigeration cycle?