wwww.removehunger.comThe 30-scrip sensitive index (Sensex) of the Bombay Stock Exchange (BSE), which opened at 18,564.08 points, was ruling at 18,440.86 points, down 65.96 points or 0.36 percent from its previous close at 18,506.82 point
Thermodynamicsis the science of energy conversion involving heat and other forms of energy, most notably mechanical work. It studies and interrelates the macroscopic variables, such as temperature, volume and pressure, which describe physical, thermodynamic systems.
First law Of Thermodynamics states thatENERGY CAN NEITHER BE CREATED NOR BEDESTROYED,ONLY ALTER IN FORM (i.e from one form to other like kinetic energy to potential energy).
First Law can be constructed to be the statement of CONSERVATION OF ENERGY.
First Law forCLOSED PROCESS CYCLE:
When a closed system undergoes a cycle then the sum of heat interactions is equal to the sum of work interactions.
Mathematically; Q(1-2)+Q(2-1)=W(1-2)+W(2-1)
OR; Q(1-2)-W(1-2)=W(2-1)-Q(2-1)
OR; [Q(1-2)-W(1-2)]+[Q(2-1)-W(2-1)]=0
OR; [Q(1-2)-W(1-2)]-[Q(1-2)-W(1-2)]=0
Since, the diffrence Q-W remains constant as long as initial and final states are same(i.e position 1 & 2).The diffrence depends only on the end points of the process .Note that Q&W are path functions i.e depends upon the path follwed by the process.But their difference does not.This implies the difference between the heat and work interactions during a process is a PROPERTY of the system and this property is called the ENERGY of the system.
Therefore we can demonstrate first law for a closed process as;
Q-W=E
E consists of ------U+K.E+P.E
For an ISOLATED system which does not interact with surroundings Q=0 and W=0.Therefore, E remains constant for such a system.
