說明:
[pageview http://physics.bu.edu/~duffy/semester1/c12_cofm_motion.html "Motion of the center of mass"]
- 質心的運動狀態可代表整體系統的運動狀態
[pageview http://physics.bu.edu/~duffy/semester1/c12_cofm_motion.html "Motion of the center of mass"]