Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Homework Help: Thermodynamics of a piston

  1. Apr 23, 2010 #1
    1. The problem statement, all variables and given/known data
    645 J of heat is transferred to 0.185 mol of air inside a cylinder with volume 0.40 L. The air is at initial pressure is 3.00E6 Pa and temperature 780K.

    Find the final temperature if the cylinder volume is allowed to increase while pressure remains constant.


    2. Relevant equations
    W=p(V2-V1)


    3. The attempt at a solution

    I have literally no idea how to do this problem. The examples in the book are (once again) unlike this problem. The question doesn't even make sense. It doesn't say what the final volume is.
     
    Last edited: Apr 23, 2010
  2. jcsd
  3. Apr 23, 2010 #2

    ideasrule

    User Avatar
    Homework Helper

    If the pressure remains constant, you know whatever work the cylinder does is given by W=p(V2-V1). Can you use dE=Q-W to solve for V2?
     
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook