研究静止和运动,必须强调参照物的作用和地位。同一物体相对于不同的参照物,它可以是运动的,也可以是静止的。同一个运动,选择不同的物体做参照物,不仅运动和静止具有相对的意义,运动的速度各不相同,而且运动的形式也不同,对物体运动的描述,选择合适的参照物尤为重要。虽然参照物的选择是任意的,但我们在研究物体的运动及比较运动物体间的速度大小时,应选地面或相对地面不动的物体作为参照物,也可以选择相对地面做匀速直线运动的物体,特别是 Study static and exercise, we must emphasize the role and status of reference. The same object can be either motionable or stationary relative to a different reference. The same movement, choose different objects as reference, not only the relative meaning of movement and rest, the speed of movement varies, and the movement of the form is also different, the description of the object movement, select the appropriate reference is particularly important. Although the choice of reference object is arbitrary, but we study the movement of objects and compare the speed of moving objects, we should choose the ground or relative to the ground as a reference object, you can also choose to do a relatively constant linear motion of the ground Objects, especially