A gas engine absorbs 2500 kJ of heat in a 5.5 s heat cycle. The amount of heat exhausted per cycle is 1800 kJ. What is a ) the efficiency of the heat engine?  b) the delivered power of the heat engine?

A heat engine is found to have an efficiency of 0.33. If it does 190 J of work per cycle, how much heat does the engine absorb and discharge each cycle? Hint   Heat absorbed: QH=QH=Incorrect J

A 67.5-kg person typically eats about 2250 kcal per day, 21.0% of which goes to mechanical energy and the rest to heat. If she spends most of her time in her apartment at 24.0°C, what is the entropy change AS of her apartment in one day? AS = kJ/K Does the entropy of the apartment increase or decrease? It decreases, because the person's entropy increases, and the net entropy change of the person and apartment is zero. It increases, because the entropy of each and every object involved in an irreversible isothermal process increases. It decreases, because the temperature of the apartment is lower than that of the person, assuming normal body temperature. O It increases, because the apartment receives heat from the person, meaning the heat transfer into the apartment is positive.

A thermal engine absorbs 1500 J of heat from a gas at a temperature of 250°K and discards 1200 J of heat as exhaust in each cycle. The temperature of the exhaust is 120° K. a) What is the mechanical work performed by the engine in each cycle? b) What is the thermal efficiency of the engine? c) What is the change in the internal energy of the engine in one cycle? d) What is the maximum efficiency that could be achieved for this particular engine? How does it compare with the actual efficiency of the engine?

A cylinder-piston system with 700 g of water at 0C is placed in a refrigerator. Water slowly freezes to ice. What is the difference between final and initial entropy of water? Latent heat of fusion for water - ice is 0.3  MJ/kg.

The temperature of the cold reservoir of the engine is 310 K. It has an efficiency of 0.23 and absorbs 647 J of heat per cycle. (a) How much work (in J) does it perform per cycle? 148.81 J (b) How much heat does it reject (in J) per cycle? 162 X J

A heat pump removes 2060 J of heat from the outdoors and delivers 3060 J of heat to the inside of a house. (a) How much work does the heat pump need?(b) What is the coefficient of performance of the heat pump?

A large electrical power station generates 1400 MW of electricity with an efficiency of 31 %. a) How much heat does the power station need to generate this amount of electricity in one day? Qn = b) How much heat is exhausted to the environment in one day? Qc = J c) The exhaust heat is transferred to the ambient air at 15 °C. What is the change in entropy of the surrounding air in one day? AS = J/K %3D d) The heat driving the generators is in the form of superheated steam at 260 °C. If a Carnot engine had been used instead, what would it's efficiency be? Efficiency = e) How much work was lost (left undone) because a Carnot engine was not used? WCarnot Wactual = %3D

An engine absorbs 500 J of heat and reject 100 J of heat to cold reservoir in each cycle.  What is its efficiency? From the last question, how much work does the engine do in three cycles?

A diesel engine has efficiency 0.180. (a) In order for this engine to do 1.24 * 10^4 J of work, how many joules of heat must it take in? (b) How many joules of this heat is discarded?