State first law of thermodynamics, Justify its mathematical equation.
Answers
The first Law of thermodynamics state which energy is well created nor destroyed , we know that the anything lost by the surrounding is gained by the whole process .
Therefore the Q and W are come as positive in the part of the ΔU=q+w and it is due to the system obtain the heat and get work done on themselves with no risk and trouble of it.
According to the first law of thermodynamics, during any transformation, there is conservation of energy.
In the case of closed thermodynamic systems, it is stated as follows:
"During any transformation of a closed system, the variation of its energy is equal to the quantity of energy exchanged with the external environment, by thermal transfer (heat) and mechanical transfer (labor). "
ΔQ = ΔU + W
where,
Q = Heat supplied to system
U = Increase in internal energy
W = Work done by system
The variation of the energy of a system which undergoes a transformation can be expressed according to the following relation:
ΔE = ΔU + ΔEc + ΔEp = W + Q
ΔE = the sum of the different energy variations of the system.
ΔU = increase in internal energy
ΔEc = the variation of the macroscopic kinetic energy of the system
ΔEp = the variation of the potential energy of the system
ΔW = Work done by system
ΔQ = Heat supplied to a system