Question

A piston cylinder device contains steam at 60 psia and 320 degree f.and the temperature is increased to 400 degree f. if the mass of the steam in the device is 15 lbm. and the weight of the piston is constant through out the process. calculate the work done during the process in btu.

Answer 1

Given: Steam in device = 60psia

Temperature = 320°

Increase in temperature = 400°

Mass of the steam = 15lbm

To Find: Work done during the process

Solution:

The process of expansion is quasi equilibrium

Thus,

Wb = ∫ PdV = P0 ∫ dv = P0 (v2-v1)

Wb = mP0 ( v2 - v1)

According to the steam table

v1 = 7.4863 and v2 = 8.3548

Substituting the value yields -  

Wb = (10) (60) ( 8.3548 - 7.4863) ( 1/ 5.404)

= 96.4 Btu

Answer: The work done during the process is 96.4 Btu.

Answer 2

Answer:

plz, find the correct solution.