Calculating Internal Energy Change: Path 2 of Carnot Cycle Question

Join the discussion
Registration is free. Start your own thread to ask a follow-up.
1 reply · 2K views
Munir M
Messages
12
Reaction score
0

Homework Statement


A gas is to be expanded from initial stage i to final stage f along either path 1 or path 2 on a p-V diagram. Path 1 consists of three steps: an isothermal expansion(work is 23J in magnitude), an adiabatic expansion(work is 35J in magnitude), and another isothermal expansion (work is 16J in magnitude). Path 2 consists of two steps: a pressure reduction at constant volume and an expansion at constant pressure. What is the change in the internal energy of the gas along path 2?

Homework Equations


ΔE=Q-W[/B]
W=nRTln(Vf/Vi)
W=∫PdV


The Attempt at a Solution


I added up the values from path 1 to be the work done, assuming that like a hess cycle the work done is same regardless of the path taken. I don't know how to get a value of Q as I don't know which equations out there work with isochoric and isobaric conditions.
 
Physics news on Phys.org
I found equations for isobaric and isochoric conditions. Q=nCpΔT and Q=nCvΔT. I still don't know how to solve it as none of the values for Cv and Cp are provided.