A. Consider two arbitrary heat engines. Engine A hasanefficiency of 60%. Engine B absorbs the same amount ofheat from theheat reservoir as Engine A; however, it exhauststwice as much heatto the cold reservoir as Engine A. Findthe efficiency of EngineB.
B. Consider a nonreversible heat engine that operatesbetweentemperatures Th and Tc, whereTc =1/3 Th. The engine absorbs anamount of heatQh from the heat reservoir in order to doan amount ofwork W.
1) If the engine discards an amount of heat Qc= 3/5Qh to the cold reservoir, determine the efficiencyofthis engine.
2) How much work, in terms of Qh, would beavailableto a Carnot heat engine operating between the same twotemperatures?What would the efficiency of this Carnot enginebe?
C. A freezer with a coefficient of performance of 4 isused toconvert 2kg of water to ice in one hour. The waterstarts at atemperature of 20°C, and the ice that is producedis cooled to atemperature of -5°C.
1) How much heat must be removed from the water for thisprocessto occur?
2) How much electrical energy does the freezer use duringthishour of operation?
3) How much heat is discarded into the room that housesthefreezer?
A. Consider two arbitrary heat engines. Engine A hasanefficiency of 60%. Engine B absorbs the same amount ofheat from theheat reservoir as Engine A; however, it exhauststwice as much heatto the cold reservoir as Engine A. Findthe efficiency of EngineB.
B. Consider a nonreversible heat engine that operatesbetweentemperatures Th and Tc, whereTc =1/3 Th. The engine absorbs anamount of heatQh from the heat reservoir in order to doan amount ofwork W.
1) If the engine discards an amount of heat Qc= 3/5Qh to the cold reservoir, determine the efficiencyofthis engine.
2) How much work, in terms of Qh, would beavailableto a Carnot heat engine operating between the same twotemperatures?What would the efficiency of this Carnot enginebe?
C. A freezer with a coefficient of performance of 4 isused toconvert 2kg of water to ice in one hour. The waterstarts at atemperature of 20°C, and the ice that is producedis cooled to atemperature of -5°C.
1) How much heat must be removed from the water for thisprocessto occur?
2) How much electrical energy does the freezer use duringthishour of operation?
3) How much heat is discarded into the room that housesthefreezer?
