Determine the components of moment of the reaction at A usin

Determine the components of moment of the reaction at A using scalar notation. I know the answer is -900, 150, -1350 Nm, but can\'t seem to get it....

The member is supported by a square rod which fits loosely through the smooth square hole of the attached collar at A and by a roller at B. The member is subjected to the forces F1 350 N, F2 450 N and F3 550 N. (Eigure 1 Figure 1 1of1 1 m 2 m 2 m

Solution

>> Let, Force Vector at C = F = F1 i - F2 j + F3 k

or, F = 350 i + 450 j - 550 k

>> Now, Rac, i.e. Position Vector From A to C = - 3 i + 2 k

>> As, Moment = R X Force [ Cross Product ]

=> Ma = Rac X F

=> Ma = (- 3 i + 2 k) X (350 i + 450 j - 550 k)

=> Ma = - 1350 k - 1650 j + 700 j - 900 i

=> Ma = - 900 i - 950 j - 1350 k