A. Find a correct statement of the 1st law of thermodynamics if kinetic and potential energy changes are negligible a. Heat transfer equals work for a thermodynamic process. b. Net heat transfer equals net work done for a closed thermodynamic cycle. c. Net heat transfer minus net work done equals internal energy change for a closed thermodynamic cycle. d. Heat transfer minus work equals internal energy for a thermodynamic process. e. The change of internal energy is not zero for a closed thermodynamics cycle

86. D A lawnmower engine with an efficiency of 0.22 rejects 9900 J of heat every second. What is the magnitude of the work that the engine does in one second?

A 39% maximum efficient coal-fired power plant needs to produce 600 MW of power.  A. To achieve maximum efficiency, if the waste water is dumped into a 13 degree Celsius lake, what temperature must the steam be heated to?  B. Since coal contains 27 kJ of energy per gram, how many kg of coal must be burned in a day?

2. As an example of microscopic thermodynamic analysis based on thermal-energy microstates, the figure to the right illustrates two systems (A and B), each containing two indistinguishable particles and possible energy levels from 1 to 8, with a particle residing in a given energy level having the same amount of energy as the level (e.g., a particle in energy-level 4 has 4 units of energy). The combined systems have a fixed total of 12 units of energy. Assuming that energy can be exchanged between the two systems, calculate the difference in entropy between condition #1 where the left-hand side has 8 units of energy and the right-hand side has 4 units of energy compared to condition #2 when the two sides reach their equilibrium condition. Note that the figure just shows one example of a configuration for condition #1. 8. 8 7 7 5 4 4 3 2 2 1 1