First law- closed system undergoing change of state, Mechanical Engineering

First Law for Closed System Undergoing Change of State - thermodynamics:

In accordance to first law, when system undergoes a thermodynamic process (change of state) heat and work transfer of both take place. The net energy transfer is stored within the system and is called as stored energy or total energy of system.

When process is executed by system the change in stored energy of system is numerically equal to the net heat interaction minus net work interaction at the time of process.

  dE = dQ - dW                                                                                                   ...(i)

  E2  - E1  = Q1-2  - W1-2

Here E is an extensive property and represents total energy of system at a given state, that is,

E = Total energy

dE = dPE + dKE + dU

If there is no change in Potential Energy and Kinetic Energy
 then, PE = KE = 0 dE = dU, putting in equation (1), we get dU = dQ - dW

or                          dQ = dU + dW

This is the 1st law of thermodynamics for the closed system. Here,

  dU = Change in Internal Energy dW = Work Transfer = PdV

  dQ = Heat Transfer = mcdT

{Heat added to system is taken as positive (+ve) and heat removal by the system is taken as negative} For a cycle              

 dU = 0; dQ = dW


Posted Date: 10/15/2012 2:13:15 AM | Location : United States

Related Discussions:- First law- closed system undergoing change of state, Assignment Help, Ask Question on First law- closed system undergoing change of state, Get Answer, Expert's Help, First law- closed system undergoing change of state Discussions

Write discussion on First law- closed system undergoing change of state
Your posts are moderated
Related Questions
Derive the mathematical expression for temperature distribution for plane wall with internal heat generation when both the surfaces are at same temperature?

what is boiler. give all things about boiler. 1 specifica 2 mounting 3 acessories 4 advantages 5 maintinance

Shear and Moment Diagrams Determine the analytical solution for the maximum stress of the beam shown; compare with stress results from Solid Works. Draw shear and moment diagra

Define Phase. A phase is a quantity of matter that is homogeneous during in chemical composition and physical structure. Determine if the matter is all gas, all liquid or all s

Normal 0 false false false EN-IN X-NONE X-NONE MicrosoftInternetExplorer4

Pattern Practices - Manufacturing processes: Pattern Practices : A pattern may be defined as a replica or fascimile model of the desired casting which, when packed or embedd

the component of computer integrated manufacturing with the diagram

The steam that leaves the super-heater is expanded from 130bar at 535°C to 25.2bar at 310°C in a high pressure turbine. The steam from the exit of the HP turbine is reheated to 535

Cellulosic Electrodes In the AWS E 6010 and E 6011 series of electrodes, the protective covering is composed of cellulose (C6H10O5) and silicate binders. The cellulose decomposes