论文部分内容阅读
［题目］（１９９９年复赛初中组）某工地在冬季水利建设中设计了一个提起重物的机械，图１是这个机械组成部分的示意图．ＯＡ是钢管，每米长受重力为 ３０ Ｎ；Ｏ是转动轴，重物的质量ｍ为１５０ ｋｇ，挂在Ｂ处，ＯＢ＝１ｍ；拉力Ｆ加在Ａ点，竖直向上．取ｇ＝ １０ Ｎ／ｋｇ
[Topic] (1999 junior high school team in the semi-finals) A site designed to lift heavy machinery in winter water conservancy construction. Figure 1 is a schematic diagram of this mechanical component. The OA is a steel pipe. The weight per meter is 30 N. The axis of rotation is O. The weight m of the weight is 150 kg, and it is hung at B. OB=1m; the tension F is added at point A, and it is upright. Take g = 10 N/kg