Rod Question

[Silverbackman]

A vertical rod of length 'l' rests on a smooth plane and starts falling over under the influence of a slight disturbance. What is the locus of 1) center of the rod 2) A point halfway between the center and the bottom 3) The top of the rod?

[OlderDan]

A vertical rod of length 'l' rests on a smooth plane and starts falling over under the influence of a slight disturbance. What is the locus of 1) center of the rod 2) A point halfway between the center and the bottom 3) The top of the rod?

"Smooth" means frictionless, so there can be no horizontal force applied to the rod. The motion of the center of mass of a rigid body is determined by the sum of forces acting on the body. How must the center of mass move? Where is the center of mass? What happens to the point in contact with the plane? What happens to the other points in question?