The “Littlewood's” hopping hoop dynamics

We present an analysis of model for the motion of massive “Littlewood's” hopping hoop. It includes the analytic conditions required for the hoop to hop and for the normal reaction force not to vanish throughout the motion, discusses the contradictory phenomenon called “quasi-jump,” and suggest that “skimming” motion is impossible in corresponding model. We find that the hoop may either hop at the first instant of release, or not at all.