-A light triangular plate OAB is in a horizontal plane.Three forces,F₁ = 2 N,F₂ = 4 N,and F₃ = 7 N,act on the plate,which is pivoted about a vertical axis through point O.In the figure,consider the counterclockwise sense as positive.The sum of the torques about the vertical axis through point O,acting on the plate due to forces F₁,F₂,and F₃,is closest to:

Question

-A light triangular plate OAB is in a horizontal plane.Three forces,F<sub>1</sub> = 2 N,F<sub>2</sub> = 4 N,and F<sub>3</sub> = 7 N,act on the plate,which is pivoted about a vertical axis through point O.In the figure,consider the counterclockwise sense as positive.The sum of the torques about the vertical axis through point O,acting on the plate due to forces F<sub>1</sub>,F<sub>2</sub>,and F<sub>3</sub>,is closest to: A) 2.2 N ∙ m B) 2.6 N ∙ m C) -2.2 N ∙ m D) -2.6 N ∙ m E) zero

Quizplus · Accepted Answer

The torque due to F1 is zero because the line of action of F1 passes through the pivot point O. The torque due to F2 is 4 N * 0.5 m = 2 N m in the counterclockwise direction. The torque due to F3 is 7 N * 1 m = 7 N m in the clockwise direction. Therefore, the sum of the torques is 2 N m - 7 N m = -5 N m. The closest answer choice is -2.2 N m.

-A Light Triangular Plate OAB Is in a Horizontal Plane