题型:问答题 简答题 如图所示,细绳一端系着质量M=0.6kg的物体,静止在水平平板上,另一端通过光滑小孔吊着质量m=0.3kg的物体,M的中点与圆孔距离为0.2m,并知M和水平面的最大静摩擦力为2N,现使此平板绕中心轴线转动,为保持物体与平板处于相对静止状态,问: (1)水平板转动的最大角速度ω为多少?(2)水平板转动的最小角速度ω为多少?(3)水平板转动的角速度ω为多少时,可使物体M与木板间摩擦力为0? g取10m/s2,结果中可保留根号。 查看答案
题型:问答题 简答题 —Do you think most of the people in Beijing can talk with foreigners in English? —Yes, I think so. ______ the young ______ the old are learning to speak English. [ ]A. Either…or B. Neither…nor C. Between …and D. Not only … but also 查看答案