Chapter 6, Problem 6.44P

A 40-lb aluminum bar, initially at Ta = 150oF, is placed in a tank together with 190 lb of liquid water, initially at Tw = 70oF, and allowed to achieve thermal equilibrium. The aluminum bar and water can be modeled as incompressible with specific heats ca = 0.216 Btu/lb·oR and cw = 0.998 Btu/lb·oR, respectively. Consider the aluminum bar and water as the system and ignore heat transfer between the system and its surroundings. Determine the final temperature Tf, in oF, and the amount of entropy produced within the tank, in Btu/oR.

Calculate the amount of work necessary for the reversible compression of steam from 1 bar to 10 bar. The compression is to take place in a cylinder fitted with a weightless piston at the constant temperature of 500 oC. Under these conditions we have a superheated vapor. Assume that steam may be treated as an ideal gas. Report your answer in units of kJ/kg using three decimal places. For conversion, note that the molar mass of water is 18.015 g/mol.

In a heat-treating process, a 10-kg metal part, initially at 1100 K, is quenched in a closed tank containing 100 kg of water, initially at 295 K.There is negligible heat transfer between the contents of the tank and their surroundings. Modeling the metal part and water as incompressible with constant specific heats 0.5 kJ/kg . K and 4.4 kJ/kg • K, respectively, determine the final equilibrium temperature after quenching, in K.

Considering air as an ideal gas,a process can be engineered by which a certain quantityof air change from thermodynamic state a to final state b, as shown in the pressure versus volume diagram. According to the information provided by the diagram and knowing thatVa = 0.070 m3,Vb = 0.110 m3P_a = 1.0 × 10^5 Pa andP_b = 1,4 × 10^5 Pa. Answer:(a) The air temperature according to the process will decrease, increase orwill it stay the same?(b) How much work will be done by air during the process?

D2

Two identical piston cylinder devices A and B both contain 1 kg of saturated water mixture at the quality ofx = 0.5 at the pressure of p = 100 kPa. Both systems are heated until the quality of the systems reach to x 0.8. However, the system in cylinder A undergoes an internally irreversible heating process but the heating in cylinder B takes place in a reversible manner. At the end of the processes when thermodynamic equilibrium is reached both systems have the same pressure of p = 100 kPa. a) What can be said about the entropy change AS of the systems A and B during these processes ? Compare them in terms of magnitude. Please explain your answer. (You do not need to calculate the exact number for the entropy change) b) Compare the two processes in terms of entropy generation. If you can express the magnitude of Sgen for any of those processes please do.

Oxygen (molar mass 32 kg/kmol ) expands reversibly in a cylinder behind a piston at a constant pressure of 3 bar. The volume initially is 0.0109 m3 and finally is 0.0348 m3; the initial temperature is 16.55 0C. Calculate the absolute temperature after expansion with the correct unit. Assume oxygen to be a perfect gas and take the specific heat at constant pressure as =  0 . 9 1 7 k J / k g K.

A substance for whichκis a constantundergoes an isothermal, reversible process from aninitial state (P1,̄V1) to a final state (P2, ̄V2).(a) Starting with the definition ofκ, show thatthe path of the process is described by:V=A(T)e−κP(b) Determine the expression which gives theisothermal work done on 1 mol of this substance

Please help!!!! Will provide helpful ratings for correct solution.