See the Bouncing Ball Flash Application in action.
The ONION SKINS screen snapshot from the Flash screen snapshot shows the EASE IN as the ball drops from the top to the floor. Notice how that movement 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 to hit the floor). See the EASE IN graph shown above here.
If you slam on your brakes in a car when you are going 75 miles per hour as you spot a deer running out on the road, and it takes you 50 yards to get stopped and 5 seconds to get stopped, where would your car be after the 1st second (of 5 seconds) of squeeling tires? It would NOT be 10 yards of the 50 yards, right? The first second your car might have gone 25 yards, or half the distance! That is easing out of the motion.
If you try to get your car up to 70 miles per hour when you pull off the shoulder onto I-380 after stopping because of the deer, how far will your car go in the first second? In the second second? In the 3rd second? That is easing into the motion. The average speed gets faster in the 2nd second than in the 1st second. So the SLOPE of the curve for the speed would be getting STEEPER.