有些数据选择题所列出的方程或方程组很难求解,甚至不能求解,这时可用反代法确定正确选项.例1如图1所示,在光滑水平面上有三个完全相同的小球排成一条直线.2、3小球静止且靠在一起,1球以速度v0射向它们,设在碰撞过程中无机械能损失,则碰后三个小球的速度分别为() Some equations or sets of equations listed in some data multiple choice questions are difficult to solve or even impossible to solve. In this case, it is possible to determine the correct options using the degeneration method. Example 1 As shown in Figure 1, there are three identical balls in a smooth horizontal plane. In a straight line, the 2 and 3 balls are stationary and close together, and 1 ball shoots them at a speed of v0. If there is no mechanical energy loss during the collision process, then the speeds of the three balls are respectively ()