路程和位移两个概念在物理教学中经常混淆不清,产生问题。本来,这是两个性质不同的物理量:路程是物体运动轨迹的长度,是标量,物体在直线上来回运动时,轨迹的长度应计算往返的路程;位移是物体运动时从初始位置指向末了位置的有向线段,是矢量,它的长度是始末两位置间的直线距离。因此两者是容易区分的。可是,在深入讨论物体运动的瞬时速度和运动方程时则产生概念上的混乱。例如,物体作曲线运动,在此时间内通过了⊿S弧长,则物体在⊿t时间内的平均速率和在t时刻的瞬时速率为 The concepts of distance and displacement are often confused and cause problems in physics teaching. Originally, these are two physical quantities with different properties: distance is the length of the object’s trajectory, and it is a scalar. When the object moves back and forth on a straight line, the length of the trajectory should calculate the round-trip distance; the displacement is the position from the initial position to the last position when the object moves. The directed line segment is a vector whose length is the straight line distance between the two positions. Therefore, the two are easily distinguishable. However, conceptual confusion arises when we discuss in depth the instantaneous velocity and motion equations of the motion of an object. For example, if an object moves in a curved line and the length of the ⊿S arc is passed in this time, the average velocity of the object in ⊿t and the instantaneous velocity in t are