Some movements involving primarily vertical or horizontal motions of the body as a whole, in which rotations can be ignored, can be studied using simple equations of linear motionin three dimensions.
有些运动主要涉及整体的垂直或水平运动，其中转动可以忽略，可以用三维线性运动的简单方程来研究。
2
So, now, what's interesting about this is we can analyze the motionin more detail.
所以，现在更有趣的是，我们可以更加详细地分析它的运动。
3
This keyboard is specially designed for people who have no motionin their hands.