7/27/2019 2012Exam1-F

1/3

Fl(j, ::: P~ VAiJ :: PU iP'" 'II;"V '7/'(" "I 'l.'/':(oroj.IJ) . = , (J) /

7/27/2019 2012Exam1-F

2/3

3: Argon is contained in a cylinder device fitted with a piston. Initially, the argon is at200 kPa and 25 C and occupies a volume of 0.5 rrr'. The argon is first compressed whilethe temperature is held constant until the volume is 0.2 m'. The argon expands while thepressure is held constant until the volume is 0.7 m". The properties of argon are R =0.2081 kl/kg-K and Cv =0.3122 kl/kgK.

a. Draw the P-V diagram for the combined process.O ~. _ 1 . .2 ' .J. m ) 9; v t': fIb. Determine the vJllime and pressure at the end of the isothermal process.

c. Determine the work transfer and the internal energy change at the end ofthe combined process.

100

p U :::m,llTm:: :P lJ /U~,n

/ 0 '1 - ~ I I" "",rY\: ;100,0,5, . . , 01,,-,(1y)1:::I.bI3k~

Argon200 kPa

Q

b ) P U ': :m R TD _ 0T / U.I,,-1">1h ' l..p " .lI.\ I' "3)[0.201 I k J ty 'k l ilqa ) / (0.1",')p ;;. : : 500 k Po,

I U l \c . ) ~ 'JI),::: m RT,K 'V\, \ V ; }\P i l ;; . ;; ' (1 .( '13 k ,'lHO,10 31 ~d/k91< ){1'1 !6 K) J , y " ( O . ? /O , S )WI). = -91,~ 3 kJ

P U ~1)1 RTT~;:; P 3 rJ 3 / f r , ' ) R )13::: 500'O.I/U,13/CU081T 3:.::10l.J3k

W 'J (il II " j~~:. I" v 3 , - 1.1 :l,IN B :::(5 0 0 kf' o ') t , '7 m ~ .~ 0 2 . tY) ~W'J.'Jj s: 150 kJ

7/27/2019 2012Exam1-F

3/3