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Why do balloons hit a wall of air?

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Rosalynn

Chemical
Feb 19, 2003
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This is not a work-related question (at least, I don't think it has any practical application, but I could be wrong!), but it's been bugging me for awhile. Figured HVAC folks would be best equipped to answer it.

Have you ever noticed that, when you hit a balloon with your hand to try to pass it to someone across the room, it goes quite fast, then all of a sudden slows down and drops? It's like it hits a wall.

Balloons don't behave like balls, which gradually slow down due to air resistance. (I can almost remember the math for it from university.) In contrast, the behaviour of balloons in air seems to go through some sort of discontinuity (when they hit that "wall"). Why is that?

I know it has something to do with the relative size of the balloon in comparison with its low mass. Also, the properties of air obviously control the situation. But which properties, and how, and why?

I'll be watching eagerly to see what people say. Equations, etc. would be fantastic.

Thanks a lot,
Rosalynn
 
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235zzzo
Your correct concerning the last post,
last post was in regards to "terminal velocity"
which was brought up by jedwards and IRstuff
read all the posts....especially Jan 19, 2004.

How is the weather in Portugal ?
 
Hi WILG!

I will, in this coming week-end to go deeper on the subject. In meantime, I'm in the middle of much work.
Sunny but rather cold, 2 - 3 ºC (or 35 to 39 ºF) during the day.

Take care.
Cheers.
zzzo
 
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