| 1. | A center of symmetry must coincide with the center of mass .
对称中心必须与质量中心重合。 |
| 2. | The velocity of the center of mass is constant in the absence of external forces .
在无外力时，质心的速度是常量。 |
| 3. | The origin is located on the axis at the point closest to the center of mass .
原点坐落在转轴上最靠近物体质心的一点。 |
| 4. | To remove the ambiguity, these laws should refer to the velocity and the acceleration of the center of mass .
要避免含糊，这些定律所指的应当是质心的速度和加速度。 |
| 5. | As another example the center of mass of the earth and moon moves in an approximately circular orbit around the sun .
作为另一个例子，地球和月亮的质心就是在一个绕太阳的近似的圆轨道上运行。 |
| 6. | To avoid ambiguity, newton's first and second laws for systems should be restated in terms of the center of mass .
为了避免意义含糊，牛顿第一定律和第二定律用于系统时，应根据质心的观点加以重述。 |
| 7. | Acceleration control of the center of mass
重心加速度制御 |
| 8. | It is strongly advised to place thrusters symmetrically compared to the center of mass of the ship
总之在布置侧推进器的时候要仔细考虑到船的运动受力结构。 |
| 9. | Also , please take into account the center of mass of the ship when you place side thrusters ( left / right / top / bottom )
同时也得把侧推进器以船身中心为轴心布置（上下/左右） 。 |
| 10. | Since the stars are orbiting around the center of mass of the binary , the visible one will move in a wavy line
由于双星会绕著共同质心运行，所以假若某星有隐形伴侣，它便会以波浪形而非一般的直线运行。 |
