( , . . , ) , S 1 S 2, (.6.3). S 1 v 1, 1 , , h 1. , S 2 v2, p 2 h 2. Δ t S 1 S 2 S′ 1 S′ 2.
, W 2 W 1 :
W 2 W 1= A, (6.3)
W 1 W 2 - S 1 S 2.
, - , , S 1 S 2, Δ t. S 1 S' 1 l 1 = υ 1Δ t S 2 S' 2 - l 2 = υ 2Δ t. , l 1 l 2 , , .6.3, υ, h. ,
= F 1 l 1 + F 2 l 2, (6.4)
F 1 = p 1 S 1 F 2 = - p 2 S 2 (, , ; .6.3).
W 1 W 2 :
W 1 = mυ 12/2 + mgh 1, (6.5)
W 2 = mυ 22/2 + mgh 2. (6.6)
(6.5) (6.6) (6.3) (6.3) (6.4),
mυ 12/2 + mgh 1 + p 1 S 1 υ 1Δ t = mυ 22/2 + mgh 2 + p 2 S 2 υ 2Δ t. (6.7)
(6.2), , , , . .
Δ V = S 1 υ 1Δ t = S 2 υ 2Δ t.
(6.5) Δ V,
ρυ 12/2 + ρgh 1 + p 1 = ρυ 22/2 + ρgh 2 + p 2,
ρ - . ,
ρυ 2/2 + ρgh + p = const. (6.8)
(6.8) . , - . , .
(6.8) ( ), ρυ 2/2 - . , ρgh .
(h 1= h2) (6.8)
ρυ 2/2 + p = const, (6.9)
|
|
p + ρυ 2/2 .
(6.9) (6.2) , , , , , . . , . , (.6.4). , , , , , .
(), . - (.6.5). , . ( 0), - (). :
0 p = ρ 0 gh, (6.10)
ρ 0 - . , , :
0 p = ρυ 2/2. (6.11)
(6.10) (6.11) :
υ = . (6.12)
, , (.6.6). , , . , . . , , . . 100 ...
. , (.6.7).
( h 1 h2 ). :
ρυ 12/2 + ρgh 1 + p 1 = ρυ 22/2 + ρgh2 + p 2.
1 2 , . . p 1 = p 2,
υ 12/2 + gh 1 = υ 22/2 + gh 2.
(6.2) , υ 2/ υ 1 =S 1/ S 2, S 1 S 2 - . S 1 >> S 2, υ 12/2
υ 22 = 2g(h 1 h 2 ) = 2 gh,
υ 2 = . (6.13)
.