Question

The forces F1={−6i+4j−2k}kN and F2={5i−5j−2k}kN act on the end of the beam. Replace these forces by an equivalent force and couple moment acting at point O.

Determine the equivalent resultant couple moment about point O.

Answer 1

The resultant equivalent force of the forces F₁ = {−6i+4j−2k} kN and F₂ = {5i−5j−2k} kN is;

  

  

  

The distance between F₁ and origin O is;

and the distance between F₂ and origin O is;

Thus the equivalent resultant couple moment at O can be calculated as;