.


:




:

































 

 

 

 


 

 

 

- , , (.13.1 13.2). , , ..

       
 
   
 

 

 


. 13.1

F
 
 
F

 

 


. 13.2

 

, , . , , , . . q (. 13.2).

, .. EJ, (. 13.3, 13.4).

(). F q , q .

. 13.3
i =1,2,3,4

. 13.4

I. :

. (13.1)

: R ;

;

.

W = 0 .

W < 0 (), .

W > 0 . .13.1: R = 3, C = 9, = 6 (13.1) W = 3 + 9 2 x 6 = 0, , , .. . . . . . , .

: .

.13.2: R = 3, C = 7, = 5, W = 3 + 7 2 x 5 = 0, .

 

II. :

W = R 3 + 3 K, (13.2)

: R ;

.

. 13.3: R = 7, K = 1, W = 7 3 + 3 x 1 = 7 .

. 13.4: R = 3, K = 0, W = 3 3 + 3 x 0 = 0, .

:

1) () , .. ;

2) SB = W - SH;

3) , SH ≠ 0 SB ≠ 0.

. 13.3: SH = 7 3 = 4 ;

SB = 7 4 = 3 , .. .

.13.5.

 

, , .. , : , , . . , -2 (. . 13.5).

 

, , NA2, , 2, - N2A. , NA2 = N2A. .

. :

1.

, () . , . 13.5. -1 -2. , N1 N2 (). : ( Y Z . 13.5). R . > 0, , < 0, . 1. N 12 N 13 (), N1A = NA1 . 1 :

, ( F 1) N 13 N 12. 2, N 23 N 24, N 21 = N 12, N 2A = N A2 . F 2. . ( . 13.5), . . 13.5 : N B5 = N A1, N B4 = N A2, N 45 = N 21, N 53 = N 13, N 43 = N 23.

()

, . , . . ( ) , . . , . 13.5 - . : N 31, N 32, N 42 () . 13.5. 3 N 31 N 32, 3: ∑ mom 3=0. N 42 , F 3,4,5 RB . N 42. , N 31 N 32. - , N 53, N 54, N B4, . 5, N B4. , N 54 N 53. F 5 RB .

, .. . ( ).

 



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