Understanding elasticity

I’ve been reading over and over the tuts on here by Pom, and Lostinbeta’s experiment on elasticity and springy effects. I’ve even went through and read Penners’ chapt.7 a few times. I still have know idea how I would adapt these methods to simply making a box appear out of no where, grow to a certain size, bounce past its limits, then retract. (you all know what I mean) I am not good with these equations at all, and don’t know how to adapt effects like these. I know this is alot to ask around here, but if anyone can help me understand. Or even show an example of how I can make a box or shape do this on its own with a onClipEvent. As opposed to mc’s following a mouse. Thanks if anyone replies.