Question

0.085 m3 of air are compressed isentropically from 1937 kPa and -4 oC to 5873 kPa . Find (a) t2 in oC and V2, (b) Wnf, and © H and U.

Answer 1

$T_2=T_1( \frac{P_2}{P_1} )^ \frac{k-1}{k}$

Where:

$T_2=$ final temperature

$T_1=269K$

$P_2=5873kPa$

$P_1=1937kPa$

$k=1.4=$ constant

$T_2=269×( \frac{5873}{1937} )^ \frac{1.4-1}{1.4} =369.3K=96.3^0C$

Also:

$\frac{T_2}{T_1} =(\frac{V_1}{V_2} )^ {k-1}$

$\frac{369.3}{269}=(\frac{0.085}{V_2})^{(1.4-1)}$

$V_2=0.0385M^3$