Question

If a rigid body rotates about point O, the sum of the moments of the external forces acting on the body about point O equals which of the following?
A) IG a

B) IO a

C) m aG

D) m aO

Answer 1

Answer:

The answer to the question is A.

Explanation:

The definition of moment is Force multiplied the distance to the point of interest.

 So the external moment at point O is equal to ⇒ EMо= F×d

 Knowing the definition of moment of inercia (I) and a newtonian Force ( m.a)

We can say that te moment of the externals force at point O is EMо= IGa

Because the rotation of a body in a inmovil point is implicated by the moment of inercia an the action of the gravity in that moment.