The key question is how long does it take to achieve that total journey is halfway done? The keyframes are at 1 and 25 for the first two panels and are at 35 and 60 for the 3rd of the 3 panels (Custom Ease In/Ease Out panels). The RED square highlights the moment when the Ball has gone exactly 50% of the distance it needs to travel to get from one KEYFRAME to the next KEYFRAME.

The horizontal axis is labeled FRAMES in the Custom Ease In/Ease Out panels (windows or dialog boxes) shown above here.

Note where the SLOPE flattens out and the ball nearly stops.

Note where the SLOPE is steeper for the EASE OUT graph.

Note how the slope of the curve is almost FLAT from frame 1 to frame 5. After Frame 20 up until Frame 25 it has a steep slope. Note where the SLOPE is steepest for the EASE IN graph.See the NO EASING graph shown above here. The moments in time are called FRAMES in Flash. The shadows or onion skins are the same distance apart at every one of the moments in time. The slope of its line is the same everywhere, indicating a constant rate of speed. Is very slow (the ball shadows are very, very close together at the top) but then becomes faster and faster (the ball shadows are farthest apart right at the bottom, where the ball is about The ONION SKINS screen snapshot from the Flash screen snapshot shows the EASE IN as the ball drops from the top to the floor.

The red ball eases in to the motion as it falls to the floor and eases out of the motion as it bounces back up from the floor.

Red bouncing ball in motion