They were also used, for example, to determine the gravitational attraction exerted by a lamina on particles . 例如：他们也用来确定一个薄片作用在一个质点上的万有引力。
Let us compare the motion of any particle of the medium with that of a second particle to the right of the first . 让我们来比较一下媒质中任一质点和其右边另一质点的运动。
The particle motion is elliptical retrograde in contrast to elliptical direct orbit for surface waves on water . 质点的运动是椭圆倒转，而不是象水上的面波那样的椭圆正转。
In this chapter we develop the implication's of momentum conservation in the motion of a collection of particles . 在本章中，我们要揭示一个质点集体作运动时动量守恒的含义。
If the reynolds number is large the flow is no longer laminar as the particles tend to move in a random manner . 如果雷诺数很大，由于流体质点变成杂乱无章的运动流动不再是层流。
Lagrange also asserted that the principle is true for a collection of particles and even for extended mass . 来格朗哥还断言，对于质点组而言这个原理也是正确的，甚至对广义质量也是对的。
When pulled to one side of its equilibrium position and released, the pendulum bob vibrates about this position . 把此质点作为摆锤拉到平衡位置的一侧，然后释放，摆锤就在平衡位置附近摆动。
Additional insight is gained by examining the elastic collision of equally massive particles in the center-of-mass frame of reference . 对质量相等的两质点的弹性碰撞更彻底的理解，可通过质心参照系而获得。
One instance of simple harmonic motion is that of the projection on any diametre of a point which describes a circular path with uniform angular velocity . 当一质点以匀角速度作圆周运动时，则它在任意直径上的投影的运动便是简谐运动的一例。
We may assume that there is no correlation between the local velocity of a liquid particle at a mathematical point inside the void space and the concentration gradient . 我们可以假定，在空隙空间的一个数学点上液体质点的局部速度和浓度梯度之间无相关性。
