[问答题]
A wheel of mass M has radius R.tjqw tru* i 40u7x-x/psnt,1c It is standing ve :*0d/f 3oved emwke9prtically on the floor, and we want t f*/0mowdpkeee:vd39 o exert 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
