The figure below shows a horizontal bar, of length 3.8 m, with
forces acting on it. A 30 N force acts at its left end, point O, in
a direction down and to the left, 45° below horizontal. A 25 N
force acts at its center, point C, in a direction up and to the
right, 30° to the right of vertical. A 10 N force acts at the right
end, in a direction down and to the right, 20° below horizontal.
3.8 m 1.9 m A horizontal rod of length 3.8 m is centered on point C.
The distance between point C and one end of the rod is 1.9 m. The
left end of the rod is labeled O. A vector labeled 30 N starts at
point O and points down and to the left at 45° below the
horizontal. A vector labeled 25 N starts at point C and points up
and to the right at 30° to the right of the vertical. A vector
labeled 10 N starts at the right end of the rod and points down and
to the right at 20° below the horizontal.
(a) What is the net torque (in N · m) on the bar about an axis
through O perpendicular to the page? magnitude N · m direction
(b) What is the net torque (in N · m) on the bar about an axis
through C perpendicular to the page? magnitude N · m direction