一、机械运动1.什么是机械运动:物理学里把物体位置的变化叫机械运动.2.运动和静止的相对性:在研究机械运动时,必须选取参照物;同一物体是运动还是静止,取决于所选的参照物;被选取的参照物既可以是运动物体,也可以是静止的物体.不管是运动的,还是静止的物体被选作参照物后,都认为是静止的,不动的. First, the mechanical movement 1. What is the mechanical movement: In physics, the change of the position of the object is called the mechanical movement. 2. The relativity of the motion and the static: When studying the mechanical movement, the reference object must be selected; whether the same object is moving or stationary, Depends on the selected reference object; the selected reference object can be either a moving object or a stationary object. Whether it is a moving or stationary object that is selected as a reference object, it is considered to be stationary and does not move. of.