III.

$(10$ points$)$:

Three control rods attached to a lever ABC exert on it the forces shown.

a$)$ Replace the three forces with an equivalent force$-$couple system at $B.(6$ points$)$

b$)$ Determine the single force which is equivalent to the force$-$couple system obtained in part a$,$ and specify its point of application on the lever. Make sure that you show your final results in a drawing. $(4$ points$)$