How to get the internal energy?

[yecko]

Homework Statement

Homework Equations

The Attempt at a Solution

v2=vf+x*vfg
x =(0.4458-0.001067)/(0.71813-0.001067) =0.61973
u2=uf+x*ufg =535.08+0.61973*(2001.8-535.08) =1444.05kJ/kg ==> far different from solution!

whats wrong with my attempt? thanks

 

[Chestermiller]

I get a value of vf at the final state of 0.816 rather than 0.718

 

[yecko]

o yes! thanks