[问答题]
A wheel of mass M has radius R. It is standing vem yk*o8ru4 x8r67cnixrtically on the floor, b,7tjonr; 17k ; zaci:.csz xut+4vmhand we want to exert a horizontal force F at its axle so that it will climb a step against which it; n7 b7hrm xcjact;itzv4 ukzs+. 1o,: rests (Fig. 8–55). The step has height h, where h
Post time 2025-2-18 20:00:22
