[问答题]
A wheel of mass M has ezfm9eg+ 814f) rqah a.cey4jradimvojuvad723*u (j yw;us R. It is standing vertically on the floor, and we want to exeru myjva*dow3j2u7v ;( t a horizontal force F at its axle so that it will climb a step against which it rests (Fig. 8–55). The step has height h, where h