The small crane is mounted along the side of a pickup bed and facilitates the handling of heavy loads. When the boom elevation angle is ? = 40?, the force in the hydraulic cylinder BC is 4.5 k N. and this force applied at point C is in the direction from B to C (the cylinder is in compression). Determine the moment of this 4.5-RN force about the boom pivot point O.

110 mm 785 mm B 340 mm 360 mm