This is the starting speed, that's the rate at which it is gaining velocity, and that's how long it's been gaining it.

这是起始时的速度,这是速度的增长速率,这是加速的时间

耶鲁公开课 - 基础物理课程节选

The angle is increasing at a steady rate, so we know it's going at a steady speed.

转过的角度以恒定速率增加,所以我们知道它以一个恒定的速度运动

耶鲁公开课 - 基础物理课程节选

It's gaining speed at some rate a.

速度的增长速率为a

耶鲁公开课 - 基础物理课程节选