While using a pencil sharpener, a student applies the forces and couple shown.

(a) Determine the forces exerted at B and C knowing that these forces and the couple are equivalent to a force-couple system at A consisting of the force R = (3.9 lb)i + Ry j ˆ’(1.1 lb)k and the couple MR/A = Mxi + (1.5 lb ft)j ˆ’ (1.1 lb ft).k

(b) Find the corresponding values of Ry and Mx.