Hi all, I'm sure this is super basic for most of you, but I'm a noob and this one has me stumped [www.tokeru.com]

1) Balls in a line that bounce one after the other (hint: use a line as your template geometry, and use a chramp to draw in a small bounce curve in with a long flat area to either side of it)

I tried this:
@P.y = sin(@ptnum+@Time*chf('speed'));

which seems kinda fine to me, except I can't figure out to incorporate that hint, of using a ramp to draw the bounce curve. I take it he means something like:

@P.y = chramp('bounce',@Time*chf('speed'));

...but then how do you get the balls to do that in sequence, one after another?

thanks! any help appreciated.