Bernoulli's Slalom

Using some household materials and some basic physics, you can have a fun game that is playable for hours.



Note: Ball may not glow as shown in the picture below.

Step 1: Gather Materials

For this project, all you need is string, clothes hangers, a hair dryer, and a ping-pong ball. You may also need an extension cord or tape.

Comments

[all_thumbs]

I am afraid that your description of how the fluid mechanics behind this game includes a number of inaccuracies. For a start, in the turbulent jet above the hair dryer, the law of Bernoulli does not even apply. Secondly, even if there was no turbulence, the pressure in the jet would not be lower that that of the surrounding air. If it was, the jet would contract real quick after the nozzle. The fan adds energy to the air in the jet, so we cannot (easily) use Bernoulli across the edge of the jet. ...and other things. To cut a long story short, small balls (small in comparison with the jet diameter) are dragged into the jet because the surrounding air is dragged into the jet. Large balls are attracted because of the Coanda effect. Still, the game works, and that's all we are interested in

[itsmanofpopsicle]

Finally! I have found someone who is as geeky as me! No insult.

[nerd12]

won't the hangers spin due to the air? though it will make more tough.

[trlgal]

so, what do you do with the hangers? you shoot the ball inside??

[falcotheimpaler]

chill out, dude... i remember doing this in Physics class in 10th grade... i never thought of making a game out of it!!! you sir, are a wonderful man.

[lemonie]

I have seen this in the windows of electical stores, when vacuum-cleaners were still an exciting buy I guess...

[naught101]

I seem to remember doing this is school with just a straw and a pingpong ball. you can do it with one of those flexy straw. can't do it for very long, but it's still fun. less energy consumption too..

[PeterTheUnGreat]

Another great idea for my Sunday school group! Pete

[JonathanS]

I've done this on a couple of children's TV shows here in the UK. The best variation we came up with used a garden leaf blower and a small mandarin orange or satsuma. Levitating soft fruit is way more fun than you'd think. Just... think carefully before you try it indoors.

[naikrovek]

I used to have a vacuum that did this. there was a ping-pong sized ball that rose up into the air when you turned the vacuum on. it was a strong vacuum, so there was still plenty of exhaust air to make it like a hovercraft also. it had no wheels, it was orange & white, and yeah it hovered and had a ping pong ball to tell you it was running - as if the intense noise wasn't enough.

[blog.darkforestdesign.com]

Really cool idea!

[dan]

use the 'no heat' setting if you have one to save power! the heater part uses 1500W, the blower part maybe 50W.

[N6OZG]

Sweet! I'm going to try this out with my boys small group.

[radiorental]

is that someone's bed in the background?