A uniform slender rod $A B$ rests on a frictionless horizontal sur-
face, and a force $\mathbf{P}$ of magnitude $0.75 \mathrm{lb}$ is applied at $A$ in a direction perpendicular to the rod. Knowing that the rod weighs $2 \mathrm{lb}$, determine
$(a)$ the acceleration of point $A,$
$(b)$ the acceleration of point $B,$
$(c)$ the location of the point on the bar that has zero acceleration.