The gibbs function of a thermodynamic system is defined by: g h - ts. if the system is consisting of two phases 1 and 2 of a single substance and maintained at a constant temperature and pressure, the equilibrium condition for the coexistence of these two phases is that the specific gibbs functions are equal consider now a first-order phase change between the phase 1 and the phase 2. at the phase boundary, the equilibrium condition for the two phases for the state a at tand p is given by gi(tp)g2lt, p) and for the neighboring state b at (t+dt) and (p+dp) is given by gi(t+dtp+dp)g(t+dtp+dp). 1- show that the specific volume of the phase i is given by: vi - 2- show that the specific entropy of the phase i is given by: s(-1 or 2).

Which of the following statements are true of solids? a.the particles do not vibrate. b.the particles are in a fixed location. c.they have strong intermolecular forces between the atoms or molecules. d.the particles have less kinetic energy than those of liquids or gases.

Under conditions for which the same room temperature is maintained by a heating or cooling system, it is not uncommon for a person to feel chilled in the winter but comfortable in the summer. provide a plausible explanation for this situation (with supporting calculations) by considering a room whose air temperature is maintained at 20â°c throughout the year, while the walls of the room are nominally at 27â°c and 14â°c in the summer and winter, respectively. the exposed surface of a person in the room may be assumed to be at a temperature of 32â°c throughout the year and to have an emissivity of 0.90. the coefficient associated with heat transfer by natural convection between the person and the room air is approximately 2 w/m2 â‹…â‹… k. what is the ratio of the thermal resistance due to convection to the thermal resistance due to radiation in the summer? what is the ratio of thermal resistances in the winter

Which of the following is the main energy source for the sun? a. fission of hydrogen b. fusion of hydrogen c. fusion of helium d. fission of iron