Laws Of Thermodynamics Flashcards
1
Q
Define the First Law of Thermodynamics.
A
Change in Internal energy = Heat energy - Work
♤U = Q - W
2
Q
Define an Isovolumetric system.
A
When there is constant volume.
* W=0
Therefore ♤U=Q
(Internal energy is caused by heating the system)
3
Q
Define an Isothermal system.
A
When there is constant temperature.
* ♤U=0
Therefore Q=W
(Heat transferred is completely used for work)
4
Q
Define an Adiabatic system.
A
Heat energy is 0
* Q=0
Therefore ♤U= -W
(Internal energy is used exclusively for work)
5
Q
Define an Isolated system.
A
-Q=0 , W=0
Therefore ♤U=0
6
Q
When is Q positive or negative?
A
When heat is ABSORBED by the system, Q is POSITIVE.
When heat us RELEASED by the system, Q is NEGATIVE.
