[问答题]
A wheel of mass M has radiud/rfbn4n+8t0(hxwgg)7x w ph s R. It is standing vertically o0b)qml t l u:g2-viji0n the floor, and we want to exert a horizontal force F at its axle so that it will climb a step against which it rests (Fig. 8–5g 002)i-jmv:tlbqu il5). The step has height h, where h
