A second accumulations

Changing velocity by accumulation

The velocity might change. You can predict those changes from the accelerations. It's the same recipe as for predicting displacements from velocities. Every second, the acceleration adds to the velocity. So the acceleration must be shown by an arrow as well because it too can be larger or smaller, but always has a direction. The acceleration adds some metressecond to the velocity each second, taking direction into account.

It's much easier with arrows, so use them, not the words!

Three kinds of arrows: Two relationships

The acceleration tells the velocity how to change(acceleration accumulates velocity). The velocity tells the displacement how to change(velocity accumulates displacement).