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Homework Help: Calculate Final volume and temperature of piston

  1. Dec 2, 2017 #1
    1. The problem statement, all variables and given/known data
    One cylinder in the diesel engine of a truck has an initial volume of 640 cm3. Air is admitted to the cylinder at 30°C and a pressure of 1.0 atm. The piston rod then does 500 J of work to rapidly compress the air. What are its final temperature and volume?

    2. Relevant equations
    I know that:
    P1 • V1 / T1 = P2 • V2 / T2
    Eth = W + Q
    And I know that work is the integral of pressure in terms of volume, but I'm not sure how to find the final values based on what I'm given.

    3. The attempt at a solution

    I set up my equation as by converting everything to SI units, so:
    P1 = 101325 Pa
    V1 = 0.64 M3
    T1 = 305.15 K

    And I know that I should be able to find the final volume based on the work done, but I don't know how.
  2. jcsd
  3. Dec 3, 2017 #2


    User Avatar
    Science Advisor
    Gold Member

    What is the difference between an isothermal and an adiabatic compression process ?
    Which compression process is used in your engine ?
    How can you use this information to solve the problem ?
    Last edited: Dec 3, 2017
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