When you adjust the easing of your motion tween, however, you can set it to either "ease in" or "ease out" of the motion, whether it's a linear point-to-point path or a rotation.
- Ease In: the motion begins slowly, before gaining speed as time progresses.
- Ease Out: the motion begins quickly, before losing speed as time progresses.
To adjust your easing settings, just click on any frame of your tween before looking in the Properties window below your stage; underneath the dropdown window that says "Tweening" with the option "Motion" selected, you'll see an option that says Ease. By default your easing is set to 0, which means that your motion continues at a constant rate of x frames per second with no changes in speed.
If you click on the arrow to the right, it will open a slider bar that lets you raise or lower the easing amount from +100 (ease out) to -100 (ease in) or any single-digit increment in between. (Next to the arrow, you'll see the text change from "In" to "Out" depending on the value selected, or remain blank if it's set to 0.) You can also type in a value in the field. Depending on how high the number value is, your motion will accelerate or decelerate more or less rapidly (the higher the number value, the faster the rate of acceleration or deceleration).