, , :
1. , , , , .
2. , , . , , . .
3. , .
4. , .
, , . , , .
6.1. G = 300 F = 500 , , , C, D A1, B1, D1. . .6.8.
.6.8
. , . , , , , , , , (.6.8).
, .
, :
, ,
, ,
. , , Ÿ . y , . z , z . , .
, , .
6.1.
|
|
6.1
|
| ||
1 | 2 | 3 | 4 |
0 | 0 | N1 | |
0 | |||
0 | 0 | N3 | |
0 | |||
0 | 0 | N5 | |
0 | -∙ | ||
0 | -F | 0 | |
0 | 0 | -G | |
|
| ||
1 | 5 | 6 | 7 |
0 | 0 | 0 | |
0 | 4∙ | 0 | |
0 | 4∙N3 | 0 | |
0 | 0 | 0 | |
4∙N5 | 0 | 0 | |
4∙ | 4∙ | -4∙ | |
0 | 0 | 4F | |
-2∙G | -2∙G | 0 |
2,3...7 , :
1) + = 0;
2) - F = 0;
3) N 1 + + N 3 + + N 5 + -G = 0;
4) 4 N 5 + 4 - 2G = 0;
5) 4 + 4 N 3 + 4 -2G = 0;
6) 4 - 4 F = 0.
F = 500
G = 300 , :
- 2) .
- 6) .
- 1) .
- 4) N5 = G/2- =150-500=-350 .
- 5) N3 = G/2- - =150 .
- 3) N1 = 0.
, , , , .6.8 , , , , . N2 N5 , .. : N2 = 500 . N5 = 350 .
6.2. ABC (.6.9) F = 30 . G = 120 . , . 6.9.
.6.9
. , . : , , , . :
, ,
.6.9. z, x y, :
1) VA + VB + VC F G = 0;
2) VA ∙1+ VB∙∙ 1 F ∙3+ G ∙0,5 = 0;
3) VC ∙1,8 + (F + G)∙0,9 = 0.
3) VC = 75 . 1) 2) VA = 22,5 ., VB = 52,5 .