F , - , , F (. 25):
M = [ rF ].
, F.
M = Frsina= Fl, (18.1)
a F; rsina = l .
z z, , 2 (.26). z z.
z , , :
z = [ rF ]z.
(.27). F , r, a - r. , , . dj ds= rdj, :
dA=F sinardj. (18.2) (18.1), dA=Mzdj,
Fr sina = Fl =Mz z. , .
:
dA = dT,
, w=dj/dt,
(18.3) .
, (. 20), ,
J ( ).
. () , n :
. r , , z.
R (.23).
dr r r+dr. dJ = r2dm ( dr<<r, , r), dm ; 2prhdr. r , dm= r 2prhdr dJ = 2prr3dr.
|
|
p R'2h , m = pR2hr,
J = 1/2R2.
, , : J Jc , , m : J = Jc + ma2. (16.1)
1
(. 1) ( , ).
14. z Lz, , . Lz z.
z ri
vi. vi; m ivi
, . . mi v i. ,
Liz = iviri (19.1)
, .
:
(17.1) vi = wri,
. .
Lz = Jzw. (19.2)
, .
(19.2) :
. .
dLz/dt= Mz
() : .
,
d L /dt= . (19.3)
=0 d L /dt=0,
L = const. (19.4)
(19.4) : , . . .
, ,