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

Some will be growing very rapidly, some will be growing less rapidly, and what this equation shows you here or that rate of growth the to the doubling time of cells.

有些会生长得更快些,有的慢一些,而这个方程告诉你,即生长的速率和细胞倍增的时间联系起来

耶鲁公开课 - 生物医学工程探索课程节选