.
, , , , . :
= mυ = , β =
.
, . mc2 = m0c2 + W
E = mc2 . , m, .
, , W =0 E = m0c2 = E0
E = E0 + W
. , , .
18. . .
. , () ().
(f) , . , .
F 0 p 0
h fF F mg
p
F S
F 0 + mg F = 0; F 0 = p 0 * S; m= ρ () * V= h*S* ρ; F=PS; p 0 S + ρ hSg pS= 0; p0 + ρ hg= p - . F a = F F 0 Fa=mg
19. . , . . . , .
. V1=V2; S1L1=S2L2; S1/S2=V2/V1-.
20.
;
.
h1 = h2 (7.3.)
, , , . , (. 7.3). , (), , , (). . (v = const), (7.3)
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|
21. , , .
, . F = ή S
C , .
η-. ;
- , .
.
Re= ; p ; v- c ; l . ; η .