Engineering Statics


The frame ACD is hinged at A and D and is supported by a cable which passes through a ring at B and is attached to hooks at G and H. Knowing that the tension in the cable is 450 N., determine the moment about the diagonal AD of the force exerted on the frame by portion BH of the cdable.

We are required to find the moment about line AD.  First 
we can choose any point on AD.  We choose A and then find 
the radius from A to any point on BH.  We choose B and get 
the value for the radius.
The length of the cable is found by geometry.
The components of the tension in cable AC are proportional 
to the geometry.
The length of AD is found by geometry.