初中应用物理知识竞赛涉及机械运动的主要知识有:一、参照物的选取我们说一个物体是在运动还是静止的,要看是以哪个物体做标准.这个被选做标准的物体叫参照物.参照物可以根据需要来选择.如果选择的参照物不同,描述同一物体的运动时,结论一般也不一样.例1在南北方向的平直公路上,有甲、乙、丙三辆汽车,甲车上的人看到乙车匀速向南,乙车上的人看到路旁的建筑物匀速向南,丙车上的人看到甲车匀速向北.这三辆车中相对于地面可能静止的是 The junior high school Applied Physics Knowledge Contest involves the main knowledge of mechanical movement: First, the reference object selection We say that an object is in motion or stationary, depending on which object to do the standard. This was chosen as a standard object called the reference object. Reference objects can be selected according to need.If the selected reference objects are different, description of the same object movement, the conclusion is generally not the same.Example 1 On the north-south straight highway, A, B, C three cars, A B car people see the vehicle to the uniform south, B on the roadside building saw people uniform speed south, the car on the truck saw a uniform car north .Three car relative to the ground may Still