申論題

1.(30%) In Fig. 1, link 2 rotates about a fixed axis O₂. The link rotates at a speed (ω2) 5 rad/sec clockwise with an angular acceleration (a2) 200 rad/sec²counter-clockwise. The link has a weight 5 kg and mass moment of inertia about the center of gravity 0.0212kg•m².

(c) (8%) Consider the gravity effect (g =9.81 n/s² and is vertically downward), then determine the external force vector F_A which is acting at point A with a direction shown in the figure to produce the given angular motion. (Hint: write the force/moment balance equations)