Answer to Question #156513 in Mechanical Engineering for Rodel

Question

A closed system undergoes a frictionless process from 200 psia and 3 ft³ during which the product pV^1.3 remains constant. How much work does the system do if the final pressure is 40 psia?

Answer 1

Q1

given innitially P₁=200psi

v₁=3Ft³

=3*1728 inch³

=5189 inch³

and finaly p₂=40psi

$\because$ PV^1.3 = constant

=>P₁V₁^1.3=P₂V₂^1.3

V₂^1.3=P₁V₁^1.3/P₂

= 200*(5184)^1.3/40

V₂=17878.6 inch³

work done = (P₂V₂-P₁V₁)/(1-r)

=(40*17878.6-200*5184)/(1-1.3)

1072186.6 lb-in

work done = 121140.82N-M