【简答题】Points【图片】 and【图片】 are any two arbitrary points in a plane figure. At a instant, the velocities of these two points are 【图片】and 【图片】, respectively; The accelerations of these two points are 【图片】and 【图...
【单选题】某跨度为6m的钢筋混凝土简支吊车梁,安全等级为二级,环境类别为一类,计算跨度l 0 =5.8m,承受两台A5级起重量均为10t的电动软钩桥式吊车,吊车的主要技术参数见下表。[2008年真题]吊车主要技术参数表(g=10m/s 2 ) 当仅在吊车竖向荷载作用下进行疲劳验算时,吊车梁的跨中最大弯矩标准值M k f (kN·m),应与下列何项数值最为接近?()
【判断题】Points【图片】 and 【图片】 are any two arbitrary points in a plane figure. The projections of the velocities of these two points on line 【图片】are 【图片】and 【图片】, respectively. The projections of the acceleratio...