[问答题]
A wheel of mass M has rad3 k:ejko2un+ue1td0d)fwa383kvp hwius R. It is standing vertically on the floor, and we want to exert a horizontal force F at its axle so that it will climb a step again8vkfh033 dpdeta1w )wst which it rests (Fig. 8–55). The step has height h, where h