一、问题如图1所示,ad、bd、cd是竖直平面内三根固定的光滑细杆,a、b、c、d位于同一圆周上,a点为圆周的最高点,d点为最低点.每根杆上都套着一个小滑环(图中未画出),三个滑环A、B、C从静止释放,用t_1、t_2、t_3依次表示滑环到达d点所用的时间,则 First, the problem is shown in Figure 1. ad, bd, cd are three fixed smooth rods in the vertical plane, a, b, c, d are on the same circle, a point is the highest point of the circle, d point is the lowest Each rod is covered with a small slip ring (not shown in the figure). Three slip rings A, B, and C are released from the rest, and t_1, t_2, and t_3 are used to indicate the time taken for the slip ring to reach point d. ,then