. . ( ) , , dm = rdV. :
(1)
r dm .
, Q. , (1):
. 1 |
(2)
r dm ( Q). X, Y, Z (. 1). dm X, Y, Z y2+z2, z2+x2, x2+y2, x2+y2+z2. X, Y, Z
,
(3)
. 2 |
, , , .
. dm (. 2) , R, ( Y) . Y
(4)
. m (. 3) R1 R2. r, dr. Y (. 3, ), (4):
(5)
. 3 |
:
(6)
, (6) R1 = 0, R2 = R, :
(7)
. (6) (7) .
(6), Q = Jy, X Z , Jx = Jz. , (3): 2Jx +Jy = 2Jy, Jx = Jy/2,
(8)
. 4 |
. m, l, R1 R2. X, (. 4). dy. , dm = mdy/l, y , . 4. X, (8)
|
|
(9)
(10)
X¢ ( )
d X¢. 13 J
(11)