In my days, they would say, "Find out when you want an object to go through that point."

我读书的时候,老师要求我,"求出物体何时经过该点"

耶鲁公开课 - 基础物理课程节选

So, what we are going to study now is a non-living object and we're going to pick it to be a mathematical point.

我们现在所要研究的的,是一个没有生命的物体,我们要把它看作一个数学上的点

耶鲁公开课 - 基础物理课程节选

So I'm going to now build an object, it's going to represent a point.

基本上说我们想要明白，这是个什么类型的对象。

麻省理工公开课 - 计算机科学及编程导论课程节选

I cannot make the object simpler than being just a mathematical point.

找不到比质点更简单的模型了

耶鲁公开课 - 基础物理课程节选

So the object is a mathematical point.

这个物体就是一个数学意义上的点

耶鲁公开课 - 基础物理课程节选

So，the point is,every object falling under gravity is given by the same formula, but there are many, many objects that can have many histories, all falling under gravity, and what's different from one object and the other object is, when was it dropped, from what height, and with what initial speed.

关键是,每一个受重力作用下落的物体,都有同样的表达式,但是各个受重力作用下落的物体,都有不同的初始条件,所以它们的区别在于,下落时刻,下落高度和初始速度

耶鲁公开课 - 基础物理课程节选