, . , , , (. 78). , , d l,
dA=Fdl=pSdl=pdV,
S , S dl=dV . ,
dA=pdV. (52.1)
A, V 1 V 2,
(52.1):
. (52.2) , .
, V. , . 79. dV pdV, . . d V . , V 1 V 2, , , p = f(V) V1 V2.
, . , . ( ), ( , ). .
, , 1 1 :
- (/()).
, , 1 1 :
v = m/M , .
- (/()).
m
= , (53.2)
.
, .
(51.2) 1 (52.1) (53.1):
CmdT = dUm + pdVm. (53.3)
, (. (52.1)) :
. . v 1 1 . (50.1),
|
|
Cv = iR/2. (53.5)
, (53.3)
, dUm/dT ( , V, ) v (. (53.4)); pVm=RT (42.4) T(p =const),
Cp = Cv + R. (53.6)
(53.6) ; , v . , , .
(53.5), (53.6)
Cv:
g=Cp/Cv=(i+2)/i. (53.8)
(53.5) (53.7) , . - . , , . , .
(. 50), Cv = 7 / 2 R. v (. 80) , Cv : (50 ) Cv= 3 / 2 R, Cv= 5 / 2 R ( 7/2 R!) v=7/2/R. , , , , .
. , ( , ). , , , ( ). , 5/2 R 7/2 R. ( -
) ( ).