An experimental device imparts a force of magnitude F 36 lb

An experimental device imparts a force of magnitude F = 36 lb to the front edge of the rim at A to simulate the effect of a slam dunk. Compute the moment of the force F about point O and about point B. The moments are positive if counterclockwise, negative if clockwise. Finally, locate a point C from the base at O to the location on the ground where the force imparts zero moment. The distance d from point O to point C is positive if C is to the right of O, and negative if to the left.

Solution

From vertical, F acts at
= arctan(5/7) = 35.5º

About B:
M = -36lb * cos35.5 * (28ft/12) - 36lb * sin35.5 * 1ft = -89.28 lb

tan35.5 = d / 10ft
d = 7.14 ft = 86 inches to the left of a point below A on the floor.
The post is 36in + 28in = 64 inches away the point below A, so
the required point is 22 inches = 1.8 ft to the left of point O