Hello

I need an expression to make a ball go up and when it reaches a certain height, it kinda oscillates, as with those popping toy clowns coming out of boxes attached to a spring...

I have tried several approaches but can't get this to work!


I'll try to explain it more clearly: I have a ball. I want it to go UP (y axis only) in a accelerated movement, which begins really fast (like an explosion) and slows down abruptely at the end
(as if it was attached to a spring); then it goes down a little, then up again, down again, etc, with its speed going down until it stops (or keeps oscillating real slowly)....

Maybe it is too complicated, and I should try another way to do this?

Please heeeeelp
thanx a lot
Daniel