Engineering Statics


A wooden board, AB, is used to support a small roof, exerting a force of 58 lb directed along AB. Determine the moment about point C.

The simplified free-body diagram is easier to interpret.
The radius is given in vector form.
The force is given in vector form using similarily with geometry.
Simplifying, the force is given as a vector.
The moment is evaluated as a determinant.
Solving the determinant gives the moment.