例1 两个宽度相同但长度不同的台球框固定在水平桌面上,从两个框的一个长边同时以相同速度分别发出A球和B球,如图1,设球在台面上的运动是匀速运动,且球与框相碰撞时不损失机械能,碰撞时问极短,可以忽略, 则 (A)两球同时回到最初出发的框边 (B)A球先回到最初出发的框边 (C)回到最初出发的框边时,两球经过相的路程 (D)回到最初出发的框边时,两球具有相同的 Example 1 Two billiard balls with the same width but different lengths are fixed on a horizontal table. A ball and a ball are issued at the same speed from one long side of the two boxes at the same time. Figure 1 shows the movement of the ball on the table. When the ball moves in a uniform motion and the ball does not lose mechanical energy when collided with the frame, the time of the collision is extremely short and can be ignored. (A) Both balls return to the original starting frame (B) A ball first returns to the original starting frame (C) When returning to the edge of the initial departure, the two balls have the same when the distance between the two balls (D) returns to the edge of the initial departure.