Question

If any external force also is applied on the distributed loading on which the moment of inertia is to be determined on the composite body then?

(a) The net force will act at the centroid of the structure only

(b) The net load will not be formed as all the forces will be cancelled

(c) The net force will act on the base of the loading horizontally

(d) The net force will not be considered, there would be a net force of the distribution, and rest will be the external forces

I got this question by my college director while I was bunking the class.

I would like to ask this question from Moment of Inertia for Composite Areas topic in chapter Moments of Inertia of Engineering Mechanics

Answer 1

The correct choice is (d) The net force will not be considered, there would be a net force of the distribution, and rest will be the external forces

To elaborate: The external forces are treated differently. They are not added by the force of the distributed loading. That is the force not only acts at the centroid always. It can be shifted also. Depending on the external forces. Thus the use of centroid or centre of mass.