它繞著質(zhì)心的橢園運(yùn)動(dòng)就幾乎看不出來(lái).Its own elliptic motion around it will be almost imperceptible.在無(wú)外力時(shí),質(zhì)心的速度是常量.The velocity of the center of mass is constant in the absence of external forces.錯(cuò)誤的根源在于混淆了質(zhì)心與重心 嗎 ?Do We Mistake Center of ...