A rigid system is subjected to two forces at point $A$ as shown in the figure below. Given $F_{AB}=85\mathrm{.}5i+128\mathrm{.}4$ j $-257\mathrm{.}1$k $($lb$)$ and $F_{AD}=63\mathrm{.}2i-189\mathrm{.}6k($lb$).$ Note that point $A$ is in $y-z$ plane.

a$)$ The magnitude of moment caused by force $F_{AB}$ about $y-$axis is $q,lb.ft$ and its direction is

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b$)$ The magnitude of moment caused by force $F_{AD}$ about $OB$ is $lb.ft$ and its direction is $1.$

c$)$ The resultant moment due to $F_{AB}$ and $F_{AD}$ about origin O is lb$.$ft

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