[问答题]
A wheel of mass M has nu.z c9dyiwt t fjz)/n m9c( l,437dthradius R. It is standing vertically abc4-d587ej,6f xx x 1tbkucnon the floor, and we want to exertxb btaf-cjceux47xkn6 51 d8, 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
Post time 2025-2-18 20:00:22
