1.
, , . , , . .
. , .
:
∑Fix = 0 = 0
∑Fiy = 0 y = 0
. ,
Fx = Fcosα
Fy = Fcosβ
Fcos (90-α) = Fsinα
F y , ; .
1?
.
, , , .
, , .
. , . : .
∑Fix = 0 ∑Fiy = 0
. , .
. . , .
1
: AB BC, F1=100H F2 = 200H.
(, B) . B.
. B.
, B . Rab; y x.
.
∑Fix = 0 1) RAB F2 + RBC cosα = 0
∑Fiy = 0 2) F1 RBC cosβ = 0 β = 90- 30 = 60
1) RAB 200 + RBC cos30 = 0
2) -100 RBC cos60 = 0
. 2 : RBC = - 100/cos60 = -100/0.5 = -200 (H)
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, RBC , .
1.
1) RAB 200 200cos30 = 0
RAB = 200 + 200cos 30 = 200(1+cos30) = 200(1+0.87) = 374 (H) , .
: RAB RBC .
. .
1 : RAB 200 + RBC cos30 = 0
374 200 + (-200)*0.87 = 374 200 174 = 0
.
: RAB = 374 H ; RBC = 200 H
1
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3. F1
F1
F2 F2
5.
F1
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1
α | β | F1 | F2 | ||
1 | 1 | 30 | 30 | 100 | 200 |
2 | 3 | 45 | 70 | 30 | 15 |
3 | 1 | 45 | 45 | 70 | 80 |
4 | 2 | 30 | - | 40 | 50 |
5 | 5 | 25 | - | 70 | 100 |
6 | 1 | 30 | 45 | 100 | 100 |
7 | 4 | 45 | - | 200 | 300 |
8 | 1 | 45 | 35 | 200 | 200 |
9 | 2 | 75 | - | 70 | 100 |
10 | 4 | 25 | - | 300 | 100 |
11 | 3 | 30 | 30 | 100 | 100 |
12 | 5 | 15 | - | 200 | 10 |
13 | 2 | 25 | - | 120 | 100 |
14 | 3 | 30 | 60 | 300 | 200 |
15 | 5 | 80 | - | 20 | 100 |
16 | 1 | 25 | 65 | 300 | 100 |
17 | 4 | 30 | - | 15 | 15 |
18 | 2 | 60 | - | 200 | 15 |
19 | 3 | 30 | 90 | 100 | 20 |
20 | 4 | 35 | - | 15 | 120 |
21 | 5 | 20 | - | 15 | 15 |
22 | 1 | 60 | 60 | 200 | 100 |
23 | 2 | 15 | - | 100 | 70 |
24 | 4 | 30 | - | 120 | 90 |
25 | 3 | 35 | 25 | 100 | 120 |
1
1. .
2. : , .
3. ?
4. .
5. .
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6. , ?
7. .