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OT: Football "Physics"

defeat-de

Should also fill the ball, and let it all settle to the declared temp.

As you fill, the air you fill with will NOT match that of the tank it escapes from, nor the wall temp of the bladder you fill with it.

A direct reading at the start of the experiment is needed. That has to be quite a while after the actual fill, and after it rests in the temperate environ the test presumes to be taken under.

The subsequent reading must be taken AFTER the ball has had settling time at the new temp as well.

Also, what is the effect caused by a severely overinflated (seam stretching) of the ball, then relax it. Do the experiment the next day. I'll bet the bladder has less "spring" tension against it then.

Does a previously "wetted" ball have leather shrinkage issues?

Reply to
DecadentLinuxUserNumeroUno
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That's not right either. If the pressure inside the ball was only 12.5 PSI it would look more like a warped pancake. The formula uses absolute pressure, not relative. You need to add in the ambient air pressure to get absolute pressure, do the math and then subtract ambient back out before you compare to the starting relative pressure.

Keep in mind that ambient will vary with altitude and less so with weather conditions. Denver average pressure is about 85% of sea level air pressure. 14.5 psi at sea level and 12 at Denver... not that they were playing in Denver, but the proper ambient pressure needs to be considered when you do the math.

--

Rick
Reply to
rickman

Nice in what way? He completely messed up the equation by using the wrong pressure and once the ball is inflated enough for the bladder to fill the ball, it is no longer very elastic since the size of the ball will change very, very little.

I see that someone got the math right at least.

--

Rick
Reply to
rickman

defeat-de

The calculation should be from absolutes.

This should be able to be extrapolated upon real world gauged readings.

Reply to
DecadentLinuxUserNumeroUno

N2 for tires is comforting if you find yourself having to use a tire inflator can sometime. Since the Freon ban, they're pressurized with butane.

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs 
Principal Consultant 
ElectroOptical Innovations LLC 
Optics, Electro-optics, Photonics, Analog Electronics 

160 North State Road #203 
Briarcliff Manor NY 10510 

hobbs at electrooptical dot net 
http://electrooptical.net
Reply to
Phil Hobbs

My, that was a HOT kick...

Reply to
Robert Baer

Kahn Academy video on deflategate (8:56) Spoiler: 5% drop in temperature, 7% drop in pressure.

-- Jeff Liebermann snipped-for-privacy@cruzio.com

150 Felker St #D
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Skype: JeffLiebermann AE6KS 831-336-2558
Reply to
Jeff Liebermann

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