A circular disk 0.3 in diameter, pivoted about a horizontal axis through its center , has a cord wrapped around its rim. The cord passes over a frictionless pulley P and is attached to a body of weight 20kg. A uniform rod 1 meter long is fastened to the disk with one end at the center of the disk. The apparatus is in equilibrium, with the rod horizontal as shown.
a. what is the weight of the rod?
b. what is the new equilibrium direction of the rod when a second body weighing 2kg is suspended from the outer end of the rod ?