Suppose a woman does 600 J of work and -9400 J of heat transfer occurs into the environment in the process. (a) What is the decrease in her internal energy, assuming no change in temperature or consumption of food? (That is, there is no other energy transfer.) AE int -10000 J (b) The internal energy is stored energy due to food intake. Treating the change in internal energy as the input energy and work done as output, what is her efficiency? % Efficiency, Eff:

A large electrical power station generates 1050 MW of electricity with an efficiency of 37.0%. (a) Calculate the heat transfer (in J) to the power station, Q, in one day. (b) How much heat transfer Q. (in J) occurs to the environment in one day? (c) If the heat transfer in the cooling towers is from 35.0°C water into the local air mass, which increases in temperature from 18.0°C to 20.0°C, what is the total increase in entropy (in J/K) due to this heat transfer? J/K (d) How much energy (in J) becomes unavailable to do work because of this increase in entropy, assuming an 18.0°C lowest temperature? (Part of Q. could be utilized to operate heat engines or for simple space heating, but it rarely is.) to Additional Materials O Reading CS Scanned with CamScanner

Suppose that a heat engine takes 3.20  104 J of heat from the high-temperature reservoir to produce 1.90  104 J of mechanical work. (a) What is the efficiency of this engine?   (b) How much waste heat does it produce?

A refrigerator does 26.0 k) of work while moving 117 kJ of thermal energy from inside the refrigerator. (a) Calculate the refrigerator's coefficient of performance. (b) Calculate the energy it transfers to its environment. kJ