在物理解题中，若涉及到两个以上的运动物体时，其“速度相等”往往是解决这类问题的关键性条件．而这个条件往往是隐含在问题中的，本文就此问题谈谈浅见．在追及问题中，速度相等往往是解题的关键条件，例如：做匀减速直线运动的物体，追赶同向做匀速直线运动的物体，恰好能? In the matter of understanding, if more than two moving objects are involved, their “equal speed” is often the key condition for solving such problems. This condition is often implicit in the problem, this article talk about this issue. In the pursuit of the problem, equal speed is often the key condition for solving the problem. For example, to make an object that moves in a straight line with a constant deceleration, to catch up with an object that is moving in the same direction and doing a uniform linear motion, exactly?