[问答题]
A wheel of mass M has radius R. It is standing vertically ffzg4j9 aqos-y q 3j(m:;q:hn on the fl o i.*tiny0i fjfu4,*loor, and we want to exert a horizontal forc 0*f4of j.iy lniuit*,e 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
Post time 2025-2-18 20:00:22
