Problem 1. The temperature of the heat reservoirs for a Carnot-cycle engine are Th = 1200K and Tc = 300K. The efficiency of the engine is calculated to be 0.75.

a) If w =-100 kJ, calculate q1 and q3. Explain the meaning of the signs.

b) The same engine can be operated in the reverse order. If w=+100 kJ, calculate q1 and q3. Explain the meaning of the signs.

c) Suppose it were possible to have an engine with a higher efficiency, say 0.80. If w= 100 kJ, calculate q1 and q3. The subscripts denote quantities for this engine. d) If we use all the work done by the engine in part c) to drive the heat pump in part b), calculate (q1 + q1) and q3 + q3), the amount of heat transferred. Explain the signs.