Final answer:
To find the resultant moment, calculate the cross product of the position vector and force vector for each force, and sum all torques to get the net torque.
Step-by-step explanation:
To determine the resultant moment produced by the forces about point O, consider each force's position vector relative to point O and the force's magnitude and direction. The moment (or torque) generated by each force is the cross product of the position vector (r) and the force vector (F), and can be calculated using torque formula τ = rF sin θ, where θ is the angle between the position vector and the force vector.
If multiple forces are present, sum up the individual torques to get the net torque. This process involves vector calculations and may require breaking the forces into components in an xy-coordinate system. It is important to use the right-hand rule to determine the direction of the torque vector.