-
8
: . 22
..
:
..
2011
1
:
F1 = 3, α = 60 
, F2 = 4, α2 = 300 
, F3 = 5H, α3 = 90
.
2. :
F1x = F1* cosα1= 3*cos 60 = 1.5 ; F1y = F1* sin α1 = 3* sin60 = 2.598 H
F2x = F2 * cosα2 = 4* cos 300 = 2 H; F2y = F2 * sin α2 = 4* sin 300 = -3.464H
F3x = F3* cosα3 = 5* cos 90 = 0 H; F3y = F3* sin α3 = 5*sin 90 = 5 H
:
F∑x = ∑Fix =1.5+2 + 0 = 3.5 H,
F∑y =∑Fiy = 2.598 3.464 + 5 = 4.134 H,
: F∑ 
= 
= 7.634 H
: α 
= arctg 
3.
.
* 100% = 
* 100% = 4,40%
*100% = 
*100% = 6,10%
: .
- F∑ 
= 7.634 , - 
= 49.765.
6%
1. . .
2. , .
3. , .
4. F1x = F1* cosα1 , α1 . 90 .
5. : .
6. , , .
7. ( )
|
|
|
2
1.:
q = 4 H/, F = 18 H, M = 15 H*, α = 60
2. :
Fx = F cos α = 18cos 60 = 9 H, Fy = F sinα = 18 sin60 = 15.5884 H
Q = q*1 = 4*4 =16 H.
3.
4. :
) ∑Mia = 0; -Q *2 Fy*9+ RB* 12 M = 0;
RB = 
) ∑MiB =0: - RAy*12 + Q *10 + Fy *9 M = 0:
RAy = 
) ∑Fix=0: RAx + Fx =0: RAx= - Fx = - 9H.
5.:
∑Fiy = 0; RAy = Q Fy + RB = 0; 18,5785 16 15,5884 + 15,6075 =2,8
:
RA = 
B-Rb = 15.6075
1. .
2. .
.
() , .
3. .
4. .
3
