1) A person consumes about 2000 kcal of food each day. Assume that 25% of this energy goes to physical work and the rest is lost as heat.
A. Draw: If their body temperature is 98.6°F, what is their daily change in entropy associated with heat loss, in kcal/K.
B. Draw: Assume that they spend their time in a room that is maintained at 25°C. What is the total change in entropy of the universe associated with heat flow from this person, in kcal/K?
2) 5 kg/min of a heavy liquid oil enters a double-pipe heat exchanger at 77?F and leaves at 220?F. Heat is supplied by saturated steam at 30 psia, which condenses to form saturated liquid water. The heat capacity of the oil is 2.0 kJ/kg K. What is the total change in entropy associated with this process?
3) 250 mol/s of ammonia vapor at -33°C and 1 atm is compressed isentropically to 10 atm. Assume that the ammonia is an ideal gas. Find the outlet temperature of the gas and the work consumed by the compressor. For this problem, take the Cp=4.269R, where R is the gas law constant.