Question $2(25$ points$)$

A closed system consisting of $1$ B $\mathrm{.}5$ lb of air undergoes a polytropic process from $p_1=80$

$lb\frac{f}{i}{n}^2.v_1=4f\frac{t^3}{l}b$ to a final state where $p_2=20lb\frac{f}{i}{n}^2,v_2=11f\frac{t^3}{l}b.$ Determine the

amount of energy transfer by work, in Btu, for the process. Unit conversion factors: $1$ Btu $=$

$778$ ft $*lbf,1ft=12in.$

Solution

FIND: Determine the work.

SCHEMATIC AND GIVEN DATA: