一、追及相遇模型【题源示例】在水平轨道上有两列火车A和B相距x,A车在后面做初速度为v0、加速度大小为2a的匀减速直线运动,而B车同时做初速度为零、加速度大小为a的匀加速直线运动,两车运动方向相同.要使两车不相撞,求A车的初速度v0满足的条件. First, chase the encounter model [title source example] There are two trains A and B on the horizontal track from the x, A car in the back to do the initial velocity v0, the acceleration of the size of 2a uniform deceleration linear motion, and B at the same time to do early Speed ​​is zero, the acceleration of a uniform acceleration linear motion, the same direction of movement of the two cars. To make two cars do not collide, find the initial speed of A car v0 meet the conditions.