Question
Consider a fully adiabatic piston-cylinder arrangement as shown in the figure. The piston is massless and cross-sectional area of the cylinder is π΄. The fluid inside the cylinder is air (considered as a perfect gas), with Ξ³ being the ratio of the specific heat at constant pressure to the specific heat at constant volume for air. The piston is initially located at a position πΏ1. The initial pressure of the air inside the cylinder is π1 β« π0, where π0 is the atmospheric pressure. The stop S1 is instantaneously removed and the piston moves to the position πΏ2, where the equilibrium pressure of air inside the cylinder is π2 β« π0.
What is the work done by the piston on the atmosphere during this process?
Options :
0
π0π΄(πΏ2 β πΏ1 )
π1π΄πΏ1 ln( πΏ1/ πΏ2)
(π2πΏ2 β π1πΏ1)π΄ /(1 β Ξ³)
Answer :
π0π΄(πΏ2 β πΏ1 )
Solution :
From the given data, V1= L1 x A
V2=L2x A
Watm = Po(V2 - V1)
= Po(L2A β L1A)
= PoA(L2 - L1)
Copyright Β© 2026 Crey All Rights Reserved