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Re: [Phys-l] cool car ... mechanical advantage ... upwind/downwind sailing ... etc



On 08/26/2011 12:20 PM, Sam Sampere wrote:

I really enjoy learning some physics from you all. Any chance we can
kiss this thread goodbye and get back to some fun?

I'll start it... This was sent on a list where we still do discuss
physics.

See you get it with about 10 s of thought... Because I didn't. Gee,
big surprise there...

http://www.dump.com/2011/07/30/under-the-ruler-faster-than-the-ruler-video/


It's the same physics as sailing directly downwind faster than the wind:
http://www.google.com/search?q=ddwfttw
e.g.
http://www.wired.com/autopia/2010/08/ddwfttw/all/1

The theory has been around for many decades:
http://projects.m-qp-m.us/donkeypuss/wp-content/uploads/2009/06/Bauer-Faster-Than-The-Wind-The-Ancient-Interface.pdf

This is also the same physics as sailing directly upwind. I witnessed a
successful example built by Chris Burges circa 1990:
https://carnot.physics.buffalo.edu/archives/1999/12_1999/msg00405.html

The same physics shows up in a turbojet engine. Here's an amusing riddle:
http://www.av8n.com/physics/jet-riddle.htm