Problems:

Word Problem	(a) Find the change in specific entropy (in kJ/kgK) when an aluminum pie pan is heated from room temperature (68 degrees F) to 450 degrees F. (b) Find the change in specific entropy (in kJ/kgK) for a copper pot experiencing the same temperature change.
3.35*	If Tsurr. = - 20oC, find:   (a) 1Q2, (b) delta-Ssys., (c) delta-Ssurr., (d) delta-Snet
3.106*	If Tsurr. = 0oC, find:   (a) 1Q3, (b) delta-Ssys., (c) delta-Ssurr., (d) delta-Snet
6.65	If Tsurr. = 300oC, find:   (a) 1Q2, (b) delta-Ssys., (c) delta-Ssurr., (d) delta-Snet

Answers:

Word Problem:	No answers will be given.
3.35*:	(a) 1Q2 = - 34.3 kJ (b) delta-Ssys. = - 0.1254 kJ/K (c) delta-Ssurr. = 0.1356 kJ/K (d) delta-Snet = 0.0102 kJ/k
3.106*:	(a) 1Q3 = - 252.44 kJ (b) delta-Ssys. = - 0.5592 kJ/K (c) delta-Ssurr. = 0.9247 kJ/K (d) delta-Snet = 0.3655 kJ/k
6.65*:	(a) 1Q2 = 436.2 kJ (b) delta-SH2 = 1.1886 kJ/K (c) delta-Ssurr. = - 0.761 kJ/K (d) delta-Snet = 0.428 kJ/k

Hints:

No hints at this time..., but you should always FIND THE PHASE if it is not given to you in the problem...
AND -- sometimes either a p-v plot or a T-s plot can come in handy...

Please Remember:

• Read EACH word.
• Draw some pictures (one for each state, or of the device).
• Write the given information under each/the picture.
• Write what you know about the process.
• Write what it is you are to find.
• If necessary, DRAW THE PROCESS ON A p-v PLOT (for closed system problems).
• Write write the equations you are to use (or might want to use).
• If necessary, find the phase at each state.
• Be sure to indicate which tables you are using.
• Be sure to use the proper "work equation" for you process.
• PLEASE try to be organized.