() , . ( ) ( ).
( ), ( ), ( , ). . (. 5.1, ) . (. 5.1, ), . (F), , :
F = -kx, (5.1)
k , ; , : F < 0 > 0, F > 0 < 0.
. (. 5.2) , , . :
(5.2)
, l .
(. 5.2) ,
(5.3)
k ,
(5.4)
(5.3) (5.1), , , . , , , , .
, , (), Fc ( ).
, , ( ):
(5.5)
, , .
. , (Fc = 0). (5.5) : .
(5.6)
, :
(5.7)
, , :
|
|
(5.8)
, j0 ( t = 0),
w0 , .
, . . t = 0.
.
, , ( ) ( ), , .
[. (5.6)], , , () : , .
(5.9)
(5.6),
(5.10)
k (5.4),
(5.11)
. . (.5.3), Acos j. w0 , j, (5.8). , , , , .
, (5.8) :
(5.12):
(5.13)
(5.13) (5.8), , , . .
(5.12), :
(5.14)
( ).
(5.14)
(5.15)
(5.15) (5.8) , , . . . , . 5.4, . 5.5.
. (), , . (5.5) , , . , , , : , r (), .
:
|
|
(5.16)
(5.16) (5.5) :
(5.17)
, :
(5.18)
:
(5.19)
b - , w0 ( ).
(5.19) , w - . w2 - b2 > 0 w (5.19) :
(5.20)
. 5.6 1; 2 :
(5.21)
0 .
:
(5.22)
:
: , b . , , , , , , :
, :
(5.23)
. 5.6 . 5.7
(b2 > w2) (5.22) , . *.
. 5.7. . 14.
* , , - , . , .