Reversible and irreversible Processes intuitive approach to reversible

Reversible and irreversible Processes intuitive approach to reversible

Reversible and irreversible Processes intuitive approach to reversible and irreversible processes later introduce entropy and the 2nd law foundation of thermodynamics Reversible process: can be defined as one whose direction can be reversed by an infinitesimal small change in some property of the system. Gedankenexperiment to picture a reversible process: 1 Make a video recording of a process Observable process 2 reversible Run the recording backwards Process impossible to observe irreversible

Examples: Process is possible reversible Backward recording reversible Backward recording x x Small changes can be reversed reversible but V1 ,Ts gas V2 ,Tf

You never observe reversed process of free expansion irreversible Reversibility is an idealization (in strictest sense, almost all real processes are irreversible) Reversibility requires equilibrium processes but Not every equilibrium process is reversible Almost perfect insulation gas in equilibrium at any time Example Tg > T0 Qout Although system in equilibrium, no small change of the system will reverse the heat flow

Reversibility is an idealization Dry friction between 2 objects You never observe the reversed process: object starts to move without assistance x Friction between piston and cylinder irreversibility Heat Conductivity in Solids (an example for irreversibility) Remember: Heat is an energy transferred from one system to another because of temperature difference T1 > T2

System 2 System 1 Heat Q flows from 1 to 2 T1 > T2 * (in the textbook T2>T1) Heat reservoir 2

Heat reservoir 1 L T(x) T1 T2 0 L x A Heat transfer per time interval through homogeneous solid object: Q K (T1 T2 )A t L K: thermal conductivity of the rod where L

A: cross-section of the rod Electric Systems (examples for reversibility and irreversibility) I #1 + battery VE - VE : work done against electrical forces per unit charge Work: W q VE dq Current I dt tf W VE ( t ) I( t ) dt

t0 Irreversible case #1 #2 Resistor network with total resistance R VE R I W R I 2 t In the steady state: Internal energy of black box unchanged 1. law: 0 U Q W U 0

Q W R I 2 t 0 Heat leaving the system Application as heater #1 reversible case Capacitor network with total Capacity C #2 q2 - Charging an uncharged capacitor W 2C q2 - Discharge of the capacitor W done by the capacitor 2C No heat transferred (Q=0)

Recently Viewed Presentations

  • Evaluation Support 2.0Sponsored by the - Evaluative Thinking

    Evaluation Support 2.0Sponsored by the - Evaluative Thinking

    Evaluation Support 2.0Sponsored by the Bruner Foundation www.evaluativethinking.organd Evaluation Services www.evaluationservices.co. Free evaluation training and technical assistance focused on development of evaluative capacity including data analysis and reporting.
  • Through the Probe Auditing of Ambient Air Monitoring ...

    Through the Probe Auditing of Ambient Air Monitoring ...

    Through the Probe Auditing of Ambient Air Monitoring Instruments at Trace Levels: Current Capabilities (Part I) & Evaluation and Comparison of an Alternative Method (Part II) Last modified by Teitz, Avraham
  • 1941-1942 Canada Plays Its Part

    1941-1942 Canada Plays Its Part

    The French government goes into exile. 1940 onward - Germany begins building up defences on 'Atlantic Wall' or 'Fortress Europe' (coast of France) Picture Analysis. You will be given a picture of a Canadian involvement during 1940-1943. With the picture...
  • Short Story Elements - metcalfe.k12.ky.us

    Short Story Elements - metcalfe.k12.ky.us

    Short Story Elements ... Setting Basic situation Characters involved Narrative Hook: question or statement that grabs the reader's attention Inciting Incident The first major action in the story that sets the story in motion (gets the ball rolling). Rising Action...
  • Chapter 10: Cinema in an International Frame

    Chapter 10: Cinema in an International Frame

    Chapter 11: Models of Film Theory Basic Models of Film Theory Realist Auteurist Psychoanalytic Ideological Feminist Cognitive Realist Theory Looks for correspondences between film images and the realities before the camera Restrictions on stylistic manipulation Andre Bazin Ethical formulation Deep-focus...
  • Globiom brazil - REDD-PAC

    Globiom brazil - REDD-PAC

    Brazilian Panel on Climate Change, 2013. Mitigating Climate Change: Contributions of the Working Group III to the First Report of the National Evaluation on Climate ChangeCOPPE. Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brasil, 405 pp. ISBN:...
  • The Immortal Life of Henrietta Lacks By Rebecca

    The Immortal Life of Henrietta Lacks By Rebecca

    Students will be able to cite specific textual evidence when writing or speaking to support conclusions drawn from the text. Students will have an elementary understanding of bioethics. 1. 2. Chapter One: Looking at the Literature 2.
  • e-handout To have these notes without taking notes

    e-handout To have these notes without taking notes

    David Stern on MJ 8.13 No, for the author could hardly have been unaware that the Mosaic Covenant presents itself as eternal; also the context shows that he is speaking only of its system of priests and sacrifices, Mtt. 26.26-29.New...