The devices measured average acceleration, meaning speed of movement, continuously over the week-long period.

这些设备在长达一周的时间里连续测量平均加速度，即运动速度。

The equation we use to describe average acceleration is a lot like the one for average velocity, because it’s just the change in velocity divided by the change in time.

我们用来描述平均加速度的方程很像平均速度的方程，因为它只是速度变化除以时间变化。