, . ( 3).
3
.
dP , . dPx , dPz .
, , .
dPx = ρqhdωcosα
dωcosα = dωz
dPx = ρqh dωz
, dωz.
ω,
x = ,
ω ( ) , , ..
, , ,
Px = ρqhωz
dPz = dPsinα = ρqhdωsinα hdωz = dV
,
V , .
, , , .
Px = ρqhωz , .
z = ρqV,
.. ρqV , , , , .
z,
,
α,
;
.
. ( 4) z. 1/3 , z. .
4
|
|
. , , .
, 1 1. .
D z
, .
, .