A uniform slender rod $A B$ rests on a frictionless horizontal surface, and a force $P$ of magnitude 0.25 lb is applied at $A$ in a direction perpendicular to the rod. Knowing that the rod weighs 1.75 lb, dib, difermine $(a)$ the acceleration of point $A,(b)$ the acceleration of point $B$, (c) the location of the point on the bar that has zero acceleration.