

Source: ZOOM
Defy Gravity! Balancing Balls on Air (Document)
BUZZ: Did you know that you can balance balls in a stream of moving air? Well, Kayla S. of Iowa City, Iowa, told us how to do it. All you need is a hair-dryer and a small, lightweight ball. Like a Ping Pong ball.
KALEIGH: Just turn your hair-dryer on. Be sure to turn it on cool and face it towards the ceiling. Put a small ball in a stream of moving air and watch. It just floats there. You can even try moving your hair-dryer from left to right and the ball still stays in the stream of moving air.
BUZZ: You're probably wondering why the air doesn't just blow the ball away. You know that the air from the hair-dryer is blowing on the ball and pushing it up. But did you know that gravity from the Earth is also pulling the ball down? That's why the ball doesn't just float up into space.
KALEIGH: So do you know what's keeping the ball from falling off from side to side? It's got to be the fast air coming from the blow-dryer. I'll show you why. If I try to balance this ruler on my fingers my hand will be holding it up and gravity will be pulling down on it. But there's nothing to keep the ruler from falling from side to side, so it just falls. But the ball doesn't fall because the air from the blow-dryer is moving very fast around the edges of the ball. The air pushes on the sides of the ball and keeps the ball from falling. The reason I know that there's air on the sides of the ball is because I can feel it.
BUZZ: It's so cool. Okay.
KALEIGH: Do you want to try two?
BUZZ: Sure. Two ball.
KALEIGH: Ready. Oh, wow!
BUZZ: Cool!
KALEIGH: You see it change like that?!
BUZZ: Awesome! They're changing position. Whoa, one fell, awesome, cool.
KALEIGH: Oh, do you want...
BUZZ: Want to try with a different...
KALEIGH: Sure.
BUZZ: Okay, let's try it with this ball. This ball looks cool. Whoa!
KALEIGH: Do you want me to catch it and put it back and try to get it?
BUZZ: Yeah, that looks fun.
KALEIGH: I know.
BUZZ: Want to throw it to me, then I'll shoot it in the air?
KALEIGH: Okay. Whoa!
BUZZ: I got it! That is so cool! It looks like there's nothing even hitting it or anything. It just floats up.
KALEIGH: It's like there's a box from the air on the ball.
BUZZ: Yeah, the air...the air, like, comes up and goes around the ball then forms again at the top.
KALEIGH: It like separates them...
BUZZ: That's so cool. Want to try it with the purple ball?
KALEIGH: Sure.
BUZZ: You can try. So cool. Wow! Wonderful.
KALEIGH: Let's see how far we can get it.
BUZZ: That's so...This might be easier to understand if you try it at home. So experiment with it.
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