EXAMPLE 5.0.7: MOMENT OF SPATIAL FORCES

Determine the moment of force F about point O.

This is a problem where the point of reference comes from the origin. 

For spatial forces, the vector method of computing moments is used. This method only requires two parameters - the position vector and the vector representation of the force.

In order to start with the vector representations, we identify the coordinates. For the position vector we can use either point B or point C.

The position vector of point B:                        

The position vector of point C:                        

The Cartesian vector form of F is

                                                    

                                                   

Using position vector B:

             

             

            

           

                                                                        ANSWER


Using position vector C:


           

          

        

                                                                        ANSWER


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