- .
( ).
| i j k |
M0(F) = r * F = | x y z | = (y*Fz - z*Fy)*i + (z*Fx - x*Fz)*j + (x*Fy - y*Fx)*k = Mox(F)*i + Moy(F)*j + Moz(F)*k
| Fx Fy Fz |
Mox(F)=y*Fz - z*Fy
Moy(F)=z*Fx - x*Fz
Moz(F)=x*Fy - y*Fx
:
. , , .
- .
F1 = -F2
R* = F1 - F2 = 0
AC/F2 = BC/(R*) ( )
(F1,F2) 0
- .
M(F1,F2) = M12 = F1*d = F2*d
.
MA = AB * F2
MA = F2 * AB * sinα = F2d
MB = BA * F1 = F1 * d
M = MA = MB = S(ACBD)
, , : , .
F1 = -F2
Mo(F2) + Mo(F1) = r2*F2 + r1*F1 = r2*F2 - r1*F2 = (r2 - r1)*F2 = AB * F2 = M(F1,F2)
.
M=Fd (). M=dF1=dF2=2SΔABC= S. ( , ).
M = M (F, F), , , .
M (F 1, F 2)= BA x F 1= AB x F 2.
:
(+ 32) )
. . .
: ) 2 , , . , , , .
) 2 , , , , .
M=M(R,R)= BA × R = BA ×(F 1+ F 2)= BA × F 1+ BA × F 2. Þ BA × F 1=M1, BA × F 2=M2, M=M1+M2.
. 2 , , 1 , .
: (F 1, F 1), (F 2, F 2)
:
. :
(Q 1, Q 1) (Q 2, Q 2). M 1= M (Q 1, Q 1)= M (F 1, F 1),
M 2= M (Q 2, Q 2)= M (F 2, F 2).
R = Q 1+ Q 2, R = Q 1+ Q 2. . . Q 1= - Q 1, Q 2= - Q 2 Þ R = - R . , (R, R ). M (R, R )= BA × R = BA ×(Q 1+ Q 2)= BA × Q 1+ BA × Q 2= M (Q 1, Q 1)+ M (Q 2, Q 2)= M (F 1, F 1)+ M (F 2, F 2) Þ M = M 1+ M 2.
:
, , , .
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M 1+ M 2++ M n=0.