一、什么是多值习题如图1所示,光滑弧形轨道AB与光滑水平轨道BC相连接,球2静止在边缘上的C点。当球1在AB轨道上某点释放,使两球发生弹性正碰后,它们落地的水平射程之比是1:4。求此两球的质量之比。对于这道试题,多数学生是这样解答的: 设球1碰前的速度为v_0,则碰后两球的速度分别为 First, what is a multi-valued exercise? As shown in Figure 1, a smooth arc-shaped track AB is connected to a smooth horizontal track BC, and a ball 2 is stationary at the point C on the edge. When the ball 1 is released at some point on the AB track, and the two balls are elastically touched, the ratio of the horizontal range they land to is 1:4. Ask for the quality ratio of the two balls. For this test question, most students answered this question: Set the speed before the ball 1 touch is v_0, then the speed of the two balls is respectively