. | ||
1 2 3 4 5 6 7 8 9 10 | 1 2 3 4 5 6 7 8 9 10 | 10 |
. 1
, | F, | , | q, / | ||
1 | 1 |
|
|
|
|
2 | 2 |
|
|
|
|
3 | 3 |
|
|
|
|
4 | 4 |
|
|
|
|
5 | 5 |
|
|
|
|
6 | 6 | 1 | 8 | 22 | 3 |
7 | 7 |
|
|
|
|
8 | 8 |
|
|
|
|
9 | 9 |
|
|
|
|
10 | 10 |
|
|
|
|
2 : . 2 2 ;
2 : . 2 2 .
2
2 , 2
. 2
. 2
3 , . 3, 3
3
3
| ||||
b x h, | ||||
1 | 1 | 10 | 92 | 4 |
2 | 2 | 10 | 80 | 4 |
3 | 3 | 10 | 100 | 4 |
4 | 4 | 10 | - | - |
5 | 5 | 10 | - | - |
6 | 6 | 8 | 80 | 4 |
7 | 7 | 10 | 100 | 4 |
8 | 8 | 10 | 100 | 4 |
9 | 9 | 12 | - | - |
10 | 10 | 12 | - | - |
4 F1; F2; F3. . ∆1 , = 2 105 /2. F1; F2; F3 1 2 4 4
4
| F1, | F2, | F3, | A1, 2 | A2, 2 | , m | |
1 | 1 |
|
|
| 2 | 4 |
|
2 | 2 |
|
|
| 2 | 4 |
|
3 | 3 |
|
|
| 2 | 4 |
|
4 | 4 |
|
|
| 4 | 2 |
|
5 | 5 | 40 | 60 | 20 | 4 | 2 | 1 |
6 | 6 |
|
|
| 4 | 2 |
|
7 | 7 |
|
|
| 2 | 4 |
|
8 | 8 |
|
|
| 4 | 2 |
|
9 | 9 |
|
|
| 2 | 4 |
|
10 | 10 |
|
|
| 4 | 2 |
|
4
. 3
. 4
1
1.
, 1, 2, . = 5 (. 5)
|
|
3=2
30 60
2=2 45 1=Р .5
|
:
1. ( ),
.
2. ( )
FAc Fab.
3. , :
P1, P2, ();
Fac Fab ().
9.
. 6
, , Fac Fab . , (). , , : - , - .
4. : .
5. . .
= FAB +FAC cos300+10cos45-10cos60 =0
= FAC sin30+10-sin600 -10sin45 -5 = 0
Fac = 7 ()
FAB + + 2 = 0; Fab = -7,95 ()
. . , . (, ).
6. (. 7). , , , , .
. 2, , . , , .
. 7
, , - , . . . . , , , .
. . , .
Fa.b = 8FAC = 7,2
Fac ( ), Fab - ( - ).
7. , . .
2 .
. 8 |
(. 8)
|
:
1. .
(- - , - - ).
|
|
2. .
3. F :
Fx = Fcos30; Fy = Fsin30.
Y |
. 9
Fx = 20cos30 = 200,87 = 17;
Fv = 20sin30 = 20x0,5 = 10.
4. (. 9). , .
1) ∑ = Fya + M RB(a + b + c) + q c(a + b +/2) = 0
10 + 10 RB(1 + 1 + 2) + 1 2(1 + 1 + ) = 0
- RB 4 + 26 = 0 RB = 6,5
2) ∑ = - q c + M Fy(c + b) + RA(a + b + c) = 0
1 2 + 10 10(2 + 1) + RA(1 + 1 + 2) = 0
RA 4 22 = 0 RA = 5,5
3) ∑xi = Fx HA = 0
17 HA = 0 HA = 17
5. :
∑yi= RA + RB Fy q c = 0
5,5 + 6,5 10 1 2 = 0 0 = 0
, , .
2 .
(. 10)
:
1. .
(- - , - - ).
2. .
3. - .
( ).
1) ∑xi = HA q 3a = 0
HA 2 6 = 0; HA = 12
2) ∑ = q 3a l,5a + F a + M Rb . 2a = 0
2 . 6 l,5 2 + 10 2 + 4 - Rb 4 = 0; Rb = 60/4=15
3) ∑Mb =RA 2a Fa . + M + q 3a 0,5a + HA a = 0
RA 4 10 2 + 4 + 2 . 6 0,5 2 + 12 2 = 0;
RA = -20/4 = -5
4. , :
∑Yi = RA + Rb F = 0
-5 +15 10 = 0 0 = 0
, , .
3.
, (. 11).
. 11
:
1. , ( 3,4).
2. 1,2,3(. 12).
C1 ; 2 ;
3 .
: x1, x2, x3, y1, y2, y3.
3. ; ( , - ).
, .
, , , :
1, 2, ;
y1 = 6,4 + 0,6 + 8,1 = 15,1 ; y2 = 6,4 + 4,05 = 10,45 ; 3 = 1,8 .
(0; 7,5) .
4. : 1,2,3
, .
4.
F1, F2, F3 (. 13). N δ . ∆ 1 ( = 2 105 /2).
. 13
:
1. , . , (. 14).
. 14
4 . :
- , ;
|
|
- (
, );
- Ni;
- ()
Ni;
- ( Z = 0) , ,
.
.
2.
.
3. () :
( )
1