It's very interesting because velocity seems to require two different times to define it -- the initial time and the final time.

这非常有趣,因为速度似乎需要两个时间才能算出来,初时刻和末时刻

耶鲁公开课 - 基础物理课程节选

Second formula tries to relate the final velocity of some time, t, to the initial velocity and the distance traveled with no reference to time.

第二个式子能把某段时间t的末速度,和初速度,经过的路程联系在一起,并且不引入时间

耶鲁公开课 - 基础物理课程节选

What is y-y0? The final y is 0, the initial y is 15. You solve for that equation and you will find the final velocity.

-y0是什么,末态的y是0,初态的y是15 你们已经得到,然后你可以找到最终速度

耶鲁公开课 - 基础物理课程节选