Final answer:
To calculate the net torque about point O, we use the torque formula T = rF sin θ which requires knowing the forces, distances from the pivot, and angles. Forces perpendicular to the lever arm exert a torque equal to the force times distance, while parallel forces exert no torque. Forces at an angle contribute a component of force that is perpendicular to the lever arm, and the torque is calculated with this component.
Step-by-step explanation:
The question asks us to calculate the net torque about point O due to the application of three forces on a pivoted body. To find this, we will use the formula for torque (T) which is T = rF sin θ, where 'r' is the distance from the pivot point to the point of application of the force, 'F' is the magnitude of the force, and 'θ' is the angle between the force and the lever arm.
For a force vector that is perpendicular to the line connecting the pivot and the point of force application, like FA in our example, the angle θ is 90 degrees, therefore sin θ will be 1. Hence, the torque will be the product of the force magnitude and the distance from the pivot, T=FA*d. If a force vector is parallel, like FB, its torque is zero since it doesn't tend to rotate the body. For a force vector at an angle, like Fc, we compute the perpendicular component, using the sin of the angle between the force and a line from the pivot. The torque is then the product of this perpendicular component and the distance to the pivot.
The specific details of the forces mentioned in this problem (FA at A, FB at B, and Fc at C, distances from O, and angles with respect to the lever arms) would allow us to calculate the net torque, if they were provided in full in the question. Without these specifics, we cannot provide a numerical answer but can explain how one would calculate the net torque once the complete information is available.