Some problems refer to a plate with a hinged bar attached to it$.$ This system is illustrated below; in different problems the coordinate axes may have different alignments with the drawing.

Question $1$

The plate shown above is rotating around the z axis with decreasing speed, the hinge attached to it is rotating around the y axis, and the link attached to the hinge is along the x axis.

There is a mass attached to the end of the link, and all other mass in the system can be neglected.

In what directions are the components of the moment vec$($M$)\_(//$A$)$ corresponding to the motion of the mass?

$^(-$y$)$

$-$x

$-$z

$+$y

$+$x

$+2$

$$ No moment

Question $2$

The plate shown above is rotating around the x axis and rotationally accelerating around the y axis. The hinge attached to it is rotating around the y axis, and the link attached to the hinge is along the x axis.

There is a mass attached to the end of the link, and all other mass in the system can be neglected.

In what directions are the components of the moment vec$($M$)\_(//$A$)$ corresponding to the motion of the mass?

$-$y

$+$y

$-2$

$-$x

$+$x

$$ Point B is not accelerating.