Chapter 5, Problem 5.26CU

Mass contains entropy as well as energy, and thus mass flow into or out of a system is always accompanied by energy and entropy transfer

1 kg of water, T1 = 300 ° C, P1 = 200 kPa in a piston-cylinder assembly passes a process to its final state at constant pressure T2 = 150 ° C by throwing heat from its initial state to the surrounding environment. At the end of this process, determine(a) Piston boundary work, (b) The amount of heat discharged from the piston to the surrounding environment, (c) The amount of entropy produced by the piston cylinder (d) The amount of entropy produced by the surrounding environment. (Take the piston cylinder surface temperature 150 ° C!)

1 kg of water, T1 = 300 ° C, P1 = 200 kPa in a piston-cylinder assembly passes a process to its final state at constant pressure T2 = 150 ° C by throwing heat from its initial state to the surrounding environment. At the end of this process, determine (a) Piston boundary work, (b) The amount of heat discharged from the piston to the surrounding environment, (c) The amount of entropy produced by the piston cylinder (d) The amount of entropy produced by the surrounding environment. (Take the piston cylinder surface temperature 150 ° C!) witer ! ambient enviroņment 1 kg

1. thermodynamics

An ideal gas undergoes a process from state 1 ( the properties are T₁ = 300 K, p₁ = 100 kPa) to state 2 (the properties are T₂ = 600 K, p₂ = 500 kPa). The specific heats of the ideal gas are: c = 1 kJ/kg-K and c = 0.7 kJ/kg-K.. The change in specific entropy of the ideal gas to two decimal places)from state 1 to state 2 (in kJ/kg-K) is......

find the changes in h  as appropriate. The initial state pressure is p1 = 0.5 MPa. the final state is 2.   a.  constant volume :                   v1 = 0.3 m3/kg,            p2 = 0.3 MPa; b. constant entropy :                    s1 = 6.3 kJ/kg K,        p2 = 0.15 MPa; c. constant volume :                    h1 = 2500 kJ/kg,          p2 = 0.2 MPa; d. constant enthalpy :                 s1 = 6.4 kJ/kg K,        p2 = 0.2 MPa;

A 60-lb aluminum bar, initially at T3 = 150°F, is placed in a tank together with 190 lb of liquid water, initially at Tw = 70°F, and allowed to achieve thermal equilibrium. The aluminum bar and water can be modeled as incompressible with specific heats c, = 0.216 Btu/lb-°R and Cw = 0.998 Btu/lb-°R, respectively. Consider the aluminum bar and water as the system and ignore heat transfer between the system and its surroundings. Determine the final temperature Tr, in °F, and the amount of entropy produced within the tank, in Btu/°R.

what can happen to the universe as entropy increases?

A divider separates 1 lb mass of carbon monoxide (CO) from a thermal reservoir at 150o F. the carbon monoxide, initially at 60o F  and 150 lbf/in2, expands isothermally to a final pressure of 10 lbf/in2 while receiving heat transfer through the divider from the reservoir. The carbon monoxide can be modeled as an ideal gas. (a) For the carbon monoxide as the system, evaluate the work and heat transfer, each in Btu and the amount of entropy produced, in Btu/oR. (b) Evaluate the entropy production, in Btu/oR, for an enlarged system that includesthe carbon monoxide and the divider, assuming the state of the divider remains unchanged. Compare with the entropy production of part (a) and comment on the difference.