in the samba, how do you do the move where you step back and do kind of a bounce on your feet?

Question

http://www.youtube.com/watch?v=sBgesLqo2iM ( 1:58)
and
http://youtube.com/watch?v=iIBHRe9Nmi0(0:43)

Answer 1

The second link doesn't work. I'm wondering what step are you reffering to, because there are many steps where you step back and bounce. But I think you're reffering to "battucadas". These kids do them in samba and in cha-cha. One way to learn it is as follows:
-First, get the footwork right. On every beat of music (every 1, 2, 3, 4) you have 3 steps. Think of them like 1-2-3, 1-2-3, each of them is a distinct step, your foot leaver the floor.
Stand with your LF prepared
1 LF back, RF off the floor
2 RF replace, LF off the floor
3 LF back, RF off the floor
The next set is similar, but it starts on the RF. Note the first set can start on the LF or on the RF, deosn't matter.
Now that you have the footwork, you can work on making it look light. Make sure your knees don't separate, keep them tight. Push the fron foot into the floor and work the hip up.
You can look it up on http://www.ballroomdancers.com but I'm not sure they cover gold syllabus. I think battucada is a gold step, but don't quote me on it. It is usually a girl's step, but in th evideo you gave the guy with a white belt is doin git the best.
Ohh, watch this one for batucadas:
http://youtube.com/watch?v=f631anLeVcY&mode=related&search=
http://youtube.com/watch?v=6FLzVxeU7bA&mode=related&search=

Answer 2

You'll note that pretty well all of samba is bouncy from the waist down, but not from the waist up. Those kids aren't beginners!
If you're talking about the spot where they're doing steps in place in 5th position, alternating right and left feet, I don't think there's a specific term for that.

Answer 3

im not really sure exactly wut move ur asking about from the video...but it mite be the whisk...? check out...

http://www.ballroomdancers.com/Dances/

go onto the samba section and they should have "whisks"
the videos teach a lot of basic moves! good luck!