This preview has intentionally blurred sections. Sign up to view the full version.
View Full DocumentThis preview has intentionally blurred sections. Sign up to view the full version.
View Full DocumentThis preview has intentionally blurred sections. Sign up to view the full version.
View Full DocumentThis preview has intentionally blurred sections. Sign up to view the full version.
View Full DocumentThis preview has intentionally blurred sections. Sign up to view the full version.
View Full DocumentThis preview has intentionally blurred sections. Sign up to view the full version.
View Full Document
Unformatted text preview: Assignment 2 D7. A ﬁ'ictionless pistoncylinder device initially contains 200 L of saturated liquid
refrigerant134a. The piston is he to move, and its mass is such that it maintains a
pressure of 800 kPa on the refrigerant. The reﬁigerant is now heated until its temperature
rises to 50°C. Calculate the work done during this process. Answer: 5227kJ ' i ll s”
301:.) D8. A pistoncylinder device contains 50 kg of water at 150 kPa and 25 '.C The
crosssectional area of the piston is 0.1 n12. Heat is now transferred to the water,
causing part of it to evaporate and expand. When the volume reaches 0.2 m3, the
piston reaches a linear spring whose spring constant is 100 kN/m. More heat 1s
transferred to the water until the piston rises 20 cm more. Determine (a) the ﬁnal
pressure and temperature and (b) the work done during this process. Also show
the process on a PV diagram. Answers: (a) 350 kPa, 138.88C; (b) 27.5 H D9. Water is being heated in a closed pan on top of a range while being stirred by
a paddle wheel. During the process, 30 U of heat is transferred to the water, and
5 k] of heat is lost to the surrounding air. The paddlewheel work amounts to 500
Nm. Determine the ﬁnal energy of the system if its initial energy is 10 kJ. Answer: 35.5 kJ D10. An insulated pistoncylinder device contains 5 L of saturated liquid water at
a constant pressure of 150 kPa. Water is stirred by a paddle wheel while a current
of 8 A ﬂows for 45 min through a resistor placed in the water. Ifonehalf of the
liquid is evaporated during this constantpressure process and the paddlewheel
work amounts to 300 1:], determine the voltage of the source. Also, show the process on a Pv diagram with respect to saturation lines. Answer: 230.9 V
”——
MBJ MW)
""0 DIE lib’0 on D11. Determine the enthalpy change Ah of oxygen, in Btu/lbm, as it is heated
from 800 to 1500 R, using (a) the empirical data for h from the oxygen table
(Table A23E), (b) the empirical speciﬁc heat equation as a ﬁmction of
temperature (Table A2Ec), (c) the C19 value at the average temperature (Table A
2Eb), and (d) the Cp value at room temperature (Table A—2Ea). Answers: (a) 169.2 Btu/lbm, (b) 170.1 Btu/lbm, (c) 178.5 Btu/lbm, (d) 153.3 Btu/lbm D12. A frictionless pistoncylinder device initially contains air at 200 kPa and 0.2
m3. At this state, a linear spring (F proportional to x) is touching the piston but
exerts no force on it. The air is now heated to a ﬁnal state of 0.5 m3 and 800 kPa.
Determine (a) the total work done by the air and (b) the work done against the
spring. Also, show the process on a Pv diagram. Answers: (a) 150 k], (b) 90 kJ A College of Engineering
———_—.
UNIVERSITY IV£/V FI%I\ ‘C/A
«#34 a FIIA/p a/
Saé 02—04 f
Af
M” : dowfﬂ'f‘ 2/, m: .2001,"L lmz i___ét___\ .. 236(9 3 /000( aoooif/IV/a’  @ 7': s’a'c «pay/"A N; : 0.019%6 ”247/ M: Fae kn’ ,1 (a0 268/093 awe ye/w a?) {2:7 2 _ 4'7,
M, zz./ A’s/4n _ 224 ,ér
[email protected] .. ’4? _ za/zésf 1.35.! 7
IV. 7,! / 4. 5 ‘5/‘21’7 w? E College of Engineering
UNIVERSITY k: we bu“ ETA/ﬂ, 74 P ’r
{’35 1/3.] 3 (c) I" V p241“; I? 1’
7., rd:
*4: Wm? 4.4.
ﬂirtd n1
3.23/79}; 53f Ade/h“ ”,4”,
“‘7’” "‘
3 . 5% College of Engineering
UNiEITY ‘ .
#ARKANSAS ‘ Dg/ ' I ‘ W/‘L A College of Engineering ———
‘ UNIVERSITY
9‘ ARKANSAS /§d k A/
mi. {I (0.00t/«o.z)o/oo3),/_n_’3 ,L /§0[Nm(ooo‘/‘l— 0007) I as, "6‘ A College of Engineering _.—_——— UNIVERSITY ‘ .
'5 ARKANSAS . I.
GIVE/V
“ We!» mm; ”m ,m.
(an tbn R"?
7/; "' /0 I41 Q3: 3427
(Your: {k7
wé. : 5'00 ”In
FLT/m
Us.
50L
4
/ 9‘ law A 514.) : AU
(30 zzr— {£7) (4 room) 7 Z72—/a,e\7 ﬁlm —.= .....— u UNIVERSITY 9/ ARKANSAS
m gags: College of Engineering
r .
_ 4 WWW .ng— Vi #3 [my
ﬂ—u/ :: 0? 64(1’65) ”My P: am?“
M :: N; @3 4/52 mt; ._. aao/afy ”’31:, ,3 4/; I a cam 51% ﬁrm!
I
m , _. —~ % 75% .. : 1:754/ % College of Engineering
UNIVERSITY
9! ARKANSAS WW..__.___.__..__ ExfanS/on Wank
(10:: floaty 3 /ﬂ(y7__yl) ./U’Z'. 5 1%ﬂ; : ﬁ.3‘(/./5’73—6.00/0J3) +ﬂé'0/ay3r 0.5% Z ' 1
’ J27 /,,‘ é « a
126 — ,7. x mm # < “:05“
Wm :: /§a ze/i/ (xvmﬁvﬁ 9? : Wifooﬁ
mt ‘ ; If
19/ ‘ éﬁ College of Engineering
UNIVERSITY , I /
# ARKANSAS wmww _____o______________________ ‘ . WJW—E; 0Xygzn J’NWV/‘_ ﬁrm! if P7,, 5 /
7? $00 ﬂ ﬂag/W 7*: Km ’2
3% F MVaF AA Aff/vj (/1) €m/p/1/f4[ézllfn frdrz &L 7254 M 55)
(5) 5540.72; APd‘f (gaﬂé’h 775/6 ﬂz" 25‘: (C) C, c3 Am. 7%” 725/! #266 (o) 9, 65 Ram WWW. far/c.1445“ A (/5‘00) : //a/7./ ”Wm M
/ > 47 gm; it A (6:06) 5' 5;{0’2.67 [#2: ,_, MW)
AA: {VV/ 29v 345 W
/$ir“a/I E’Yv/fa
— /W
5,, = a +327“ #7“ %A73 4%?
4 (.ﬂFJ‘
4 5 0 .20/7 X/aﬁ
c s — ﬂadj'QVf 470‘
of: amvz my? 1 AA :— 54¢er I /500
A4 3 W 7‘25; r1 71;} (‘7;% 75479/
7 (4W5)(/5W) 7‘ [{j/aJa/OF Z)(/;g:&; L
+(é)é&,o;,z75' E ’5')(/J‘00)3 ﬂywwfjhgﬁk/W)?
“ @0957(900) "(U/5.20271; ~;)(?w)‘  (312/ c.&5'275 g 5) <f%)3"/:/l)(a0f3 72 2F .79) (800)” 44 3 ‘7'3/2’7‘5 7A 2,2521 + “52547 + 47?? gm;
“ 975:4 5' €9ﬁﬁ7~(“7¢.aj) — £11570 £14 : 5:5”??m? 5"“...
/é.ﬂ":,j AA 5377,? ﬁg 2: gm ..., /Mw
Alm/ 3 z 5m _. I / 24b E NEE! College of Engineering U IVERSITY g! ARKANSAS (90 “29227.7: 190,949)
Man/Z C
001/1 ﬁt;
4m k
547 : 0,,213 W) /_<§ﬂ@’
/:’/97 /Z l A College of Engineering ———UNV3N;1  . D 2'
,r C $an 72‘: t
A,“ y ﬂ: lelm 405‘ 00“
y': i 10" ﬁ': 0 {n3
Sid/lg ‘bvtju/O
E. a
ETA/b F. (A) Tm/ Work pm 1,; AL
LB) w Mm an SPF/r» SolUTION (/1) U: Vl’alfl: ﬁrm arwér Cum/t W? (ﬂ) A‘bz = (20a 7*?05% 1‘ 5 4M ...
View
Full Document
 Spring '09
 Davis

Click to edit the document details