3
, .4 ( ) .5 ( ), :
1) Q . Q ;
2) ;
3) (.8): a - , D D - . ;
4) , 3;
5) (.8) .
2
1. , .4¸6 3 ( 1). , 516 3 () 1 2 - 1 = 15, 2 = 5, = -15×.
( - ); , . , . l 1 = 1,4, l 2 = 0,5, l 3 = 1,6 h 1 = 0,10, h 2 = 0,02, b = 0,12. .
Q . () . , , . , , , . Q , , .
Q , , Q . , , , Q , . , . 1, P 2 , (. 6).
2. .
3.
,
W . , F , l - , r - ( ).
|
|
4.
, . .
5.
,
.
() , . :
y , i , Z; Si , Fi . . JZi , , . Z; . Z, ,
Z, y.
Q (.6).
1. R , . ( , ).
RA = 5, MA = 0.
:
, .
2. I, II, III 1-2, 2-3, 3-4 . . 6 .
3. Q , . , , . Q .
( Q M ):
I
Q 1 = RA = 5, Q 2 = RA = 5
M 1 = MA + R A × 0 = 0, M 2 = M 2 + RA × l 1 = 5
II
Q 2 = RA - P 1 = -5, Q 3 = RA - P 1 = -5
M 2 = MA + RAl 1 - P 1 × 0 = 5
M 3 = MA + RA (l 1 + l 2) - P 1 l 2 = -5
III
Q 3 = RA - P 1 = -5, Q 4 = RA - P 1 = -5
M 3 = MA + RA (l 1 + l 2) - P 1 × l 2 + M = 15
M 4 = MA + RA (l 1 + l 2 + l 3) - P 1(l 2 + l 3) + M = 0
4. Q .
, :
|
|
III
Q 4 = - P 2, Q 3 = - P 2 = -5,
4 = P 2 × 0, M 3 = P 2 × l 3 = 15
II
Q 3 = - P 2 = -5, Q 2 = - P 2 = -5
M 3 = P 2 × l 3 - M = -5, M 2 = P 2(l 2 + l 3) - M = 5
I
Q 2 = - P 2 + P 1 = 5, Q 1 = - P 2 + P 1 = 5,
M 2 = P 2(l 2 + l 3) - M - P 1 × 0 = 5, M 1 = P 2(l 1 + l 2 + l 3) - M - P 1 × l 1 = 0
- (.7) :
1. S MA = RA × 0 - P 1 l 1 - M + RB (l 1 + l 2 + l 3) = 0
S MB = - RA (l 1 + l 2 + l 3) + P 1(l 2 + l 3) M + RB × 0 = 0
RB = 5, RA = 5
: S Y = RA - P 1 + RB = 0 (!)
,
2. I, II, III 1-2, 2-3, 3-4.
3. Q :
I
Q 1 = RA = 5, Q 2 = RA = 5
M 1 = RA × 0 = 0, M 2 = RA × l 1 = 5
II
Q 2 = RA - P 1 = -5, Q3 = RA - P 1 = -5
M 2 = RAl 1 - P 1 = 0 = 5,
M 3 = R1(l 1 + l 2) - P 1 l 2 = -5
III
Q 3 = RA - P 1 = -5, Q 4 = RA - P 1 = -5,
M 3 = RA (l 1 + l 2) - P 1 l 2 + M = 15
M 4 = RA (l 1 + l 2 + l 3) - P 1(l 2 + l 3) + M = 0
4. () Q . ,
III
Q 4 = - RB = -5, Q 3 = - RC = -5,
M 4 = RB × 0 = 0, M 3 = RB × l 3 = 15
II
Q 3 = - RB = -5, Q 2 = - RB = -5,
M 3 = RB × l 3 M = -5, M 2 = RB (l 3 + l 2) M = 5
I
Q 2 = - RB + P 1 = 5, Q 1 = - RB + P 1 = 5,
M 2 = RB (l 3 + l 2) - P 1 × 0 M = 5, M 1 = RB (l 3 + l 2 + l 1) - P 1 × l 1 - M = 0.