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2017年4月浙江省物理选考卷第20题是一道力学综合题,考查动能定理与圆周运动的相关知识,综合性较强.但笔者觉得此题存在值得商榷之处.1真题再现图中给出了一段“S”形单行盘山公路的示意图.弯道1、弯道2可看作两个不同水平面上的圆弧,圆心分别为O_1、O_2,弯道中心线半径分别为r_1=10 m、r_2=20m,弯道2比弯道1高h=12m,有一直道与两弯道相切,质量m=1200kg的汽车通过弯道时做
April 2017 Zhejiang physical selected test paper No. 20 is a comprehensive mechanics questions, examining the kinetic energy theorem and circular motion related knowledge, strong comprehensive, but I think this question is debatable. A curve of “S ” shaped single-lane winding road is shown in Figure 1. Curve 1, curve 2 can be regarded as arcs on two different horizontal planes, the centers of which are O_1 and O_2, respectively, and the radius of centerline of curve is r_1 = 10 m, r_2 = 20m, curve 2 higher than the curve 1 h = 12m, there is a straight line with two corners tangent, mass m = 1200kg when the car through the curve to do