. , . , , . .
. , p m V: p = m V.
mdV
= d p = F, (1.3.1)
dt dt
F .
, , :
N
F = å F i = 0. (1.3.2)
i =1
(1.3.1), (1.3.2)
d p = 0. (1.3.3)
dt
:
N
p = å p i = const. (1.3.4)
i =1
, : , , , .
. . , , . ∆A F, , Δ r :
A A = (F, Δ r) = F A r cosα. (1.3.5)
(1.3.5) cos α.
, , , . , ( ),
. , .
, : , , , , .
, , . , . , (, ó) . , . , . , , .. , . , , .
|
|
, :
E2 E1= ∆A. (1.3.6)
. .
mV 2
W =.
(1.3.7)
. ().
, . .
, , , . , .
2 2
U= ƒ1 (Fdy) = ƒ1 mgdy= mgy2 mgy1. (1.3.8) , , , . , , . .
:
E= E+ U. (1.3.9) , .. ,
E= E+ U = const, (1.3.10) .. , . .