2. A 60-W incandescent light bulb runs continuously for 100 days. Use 3 significant digits in your answers. (a) Calculate the amount of energy used, in joules and in kilowatt hours. (b) How much heat is produced if the bulb has an efficiency of 5.00 percent?

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

5. A heat engine with a high temp reservoir at 400K has an efficiency of 0.20. What is the max possibletemp of the cold reservoir?

3. The specific Helmholtz Free energy f is related to the specific internal energy u as: ƒ (T, a) = u — Ts where the "natural variables" of f are temperature and specific volume. a. Expand the differential off in terms of partial derivatives with respect to the natural variables of f b. Using the result from a. and applying the 1st Law of Thermodynamics, what are af T and of la? θα c. From the equality of mixed partial derivatives, show that Op ari la əs θα