The intent of this research is to study the dynamic behavior of a solid body resting on a moving surface. Results of the study are then used to propose methods for controlling the orientation of parts in preparation for automatic assembly. Two dynamic models are discussed in detail. The first examines the impacts required to cause reorientation of a part. The second investigates the use of oscillatory motion to selectively reorient parts. This study demonstrates that the dynamic behaviors of solid bodies, under the conditions mentioned above, vary considerably with small changes in geometry or orientation.