文档介绍：Thermal Energy Problem Set #2 – Fall 2002
Time spent on problems:
Problem 1:
Problem 2:
Problem 3:
Problem 4:
Problem 5:
Problem 6:
Thermal Energy Problem Set #2 – Fall 2002
Do all problems. Please use a separate sheet of paper for each problem.
1. Two different fuels can be used in a heat engine, operating between the fuel-burning
temperature and a low temperature of 350 K. Fuel A burns at 2500 K delivering
52,000 kJ/kg and costs $ per kilogram. Fuel B burns at 1700 K, delivering 40,000
kJ/kg and costs $ per kilogram. Which fuel would you buy and why?
2. Two heat reservoirs (500 K and 300 K) operate a Carnot engine between them. (a) If
the engine receives 1000 J from the 500 K reservoir, what heat is rejected to the 300 K
reservoir? (b) If the engine were operated in reverse as a refrigerator and received
1000 J from the 300 K reservoir, what heat is delivered to the 500 K reservoir? (c)
What is the mechanical work required to operate the refrigerator in (b)?
3. Problem . VW, S&B. pp. 247.
4. a) A simple engine uses a perfect gas as the working fluid in a piston-cylinder
system. The gas is first heated at constant pressure from state 1 to state 2, then
cooled at constant volume to state 3 where T3=T1, and then cooled at constant
temperature, thereby returning to state 1. Derive expressions for the