1·For an object to be in rotational equilibrium about a certain point, the total torque about this point must be zero.
一个物体若要在某一点处处于转动平衡，在这一点处的总力矩必须为零。
2·In art and design, rotational symmetry can be used to portray motion or speed.
在艺术和设计中，转动对称可以用来表达动作和速度。
3·We could worry about its vibrational or rotational energy, or electronic state.
我们也需要知道，他的振动和转动能量，或者电子状态。
4·Each of these impact events would also have significantly affected the rotational state of the Moon, causing the solid mantle and liquid core to rotate differently.
每次撞击都会对月球的转动状态产生重大的影响，并引起坚固的地幔和液体磁芯间的转速差异。
5·Each year, the Moon steals some of Earth's rotational energy, and USES it to propel itself about 3.8 centimeters higher in its orbit.
每年，月球都会偷取地球的部分转动能，让自己在运行轨道中的位置升高大约3.8厘米。
1·Elevation, tilt, overhead reach, and rotational motion features allow easy access and appropriate positioning of objects.
高程，倾斜，高架延伸和回转运动的特点，可轻松对物体进行适当的定位。
2·There is no need to control the rotational position about the axis of the bore, because up to the time when the holes are drilled, it is symmetrical about that axis.
由于直至钻这些小孔时，工件都对称于大孔轴线，所以没必要控制围绕大孔轴线回转的位置。
3·If this is not done, the rotational momentum of the spool will cause it to remain in motion allowing yarn to be unwound without being taken up.
如果不能做到这一点，筒子的回转力矩会使它继续转动并退绕纱线，而退绕的纱线不能被卷绕到新卷装上。
4·This paper presents a method with mixed spectra for analyzing rotational accuracy of spindles, making use of the modified periodogram test combined with dynamic data system modeling.
本文采用动态数据系统建模分析法与改进的周期图检验法相结合，对主轴回转精度进行混合谱分析。
5·And the development of different kinds of plastics for rotational molding especially PE were discussed.
探讨了可用于回转成型的各类塑料，尤其是聚乙烯的研究开发情况。