So, when I threw that thing up and you caught it, what you are doing mentally was immediately figuring out where it started and at what speed.

所以当你接住我抛出的物体时,你大脑里的反应就是,立刻弄清它的初位置以及初速度

耶鲁公开课 - 基础物理课程节选

When does it hit the ground and at what speed?"

该物体何时落地,落地速度是多少

耶鲁公开课 - 基础物理课程节选

If you're a doctor and you've got a patient who's running away from you at the speed of light, you'll know what to do.

如果你是个医生,你的一个病人以光速逃跑了,你就知道该怎么办了

耶鲁公开课 - 基础物理课程节选

What it means is if you'd release a rock at that location one second before with a certain speed that we can calculate, it would've ended up here with precisely the position and velocity it had at the beginning of our experiment.

它的意义在于,若在该处以特定速度抛出一个物体,这个速度可通过计算得到,一秒之后,物体会运动至我们设定的起点,并且速度为我们设定的初速度

耶鲁公开课 - 基础物理课程节选