C1993M3. A long, uniform rod of mass M and length l is supported at the left end by a horizontal axis into the page and perpendicular to the rod, as shown above. The right end is connected to the ceiling by a thin vertical thread so that the rod is horizontal. Express the answers to all parts of this question in terms of M,L and g .
a. Determine the magnitude and direction of the force exerted on the rod by the axis.
b. If the breaking strength of the thread is 2 Mg , determine the maximum distance, r , measured from the hinge axis, that a box of mass 4 M could be placed without breaking the thread