For the Patriots to blame a change in temperature for 15% lower-pressures, requires balls to be inflated with 125-degree air.

— Neil deGrasse Tyson (@neiltyson) January 26, 2015

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NDT is actually incorrect there, he counted the PSI above air pressure as the total air pressure. The total air pressure in a ball that is 12 PSI above air pressure is 26 PSI and that's the number that needs to be used to convert to the temperature.

standard Ideal Gas Law:

 

pV=mR*T

 

p=pressure (psi), gauge pressure plus atmospheric pressure

V=volume (in3)

m=mass

R*=gas constant

T=temperature ®

 

You have scenario 1 (indoors, 70F) and scenario 2 (outdoors, 50F). Mass, volume and gas constant are constant for both, so the equation can be rewritten as:

(p1V1/mR*T1)=p2V2/mR*T2)

p1/T1=p2/T2

 

p1=12.5 psi (gauge pressure) + 14.7 psi (atmospheric pressure) = 27.2 psi

T1=70F=529.67R

T2=50F=509.67R

 

p2=p1T2/T1

 

p2(gauge)=26.2-14.7=11.5 psi

 

 

So that's a psi drop just from the temperature change. I really doubt that the NFL rules are detailed enough to state the temperature at which the ball's pressure should be measured.

Guys I already posted the correct equations.

Edited January 27, 201511 yr by StrangeSox

Switch over to the pro bowl to see Andy Dalton...Dafuc? Cutlers numbers were better pretty much across the board.

Cutler has bad body language and doesn't look at the previous drive's plays on the bench. He just sits by himself and frowns. Didn't you hear?

STOP THE PRESSES THEY FOUND THE BALL BOY WHO DID IT!!!!!!!!!!!!!!!!

 

And he took the balls to the bathroom and made sweet love to them! !!.

Guys I already posted the correct equations.

 

Well, technically, "m" is the number of gas molecules...

 

 

Well, technically, "m" is the number of gas molecules...

that's for pV=nRT

SS what do you do for a living again?

that's for pV=nRT

 

That would be the ideal gas law I always learned. If you wanted to include mass, wouldn't you have to divide by the molar mass? ... Obviously the m/n is constant, so the whole conversation is moot

 

 

That would be the ideal gas law I always learned. If you wanted to include mass, wouldn't you have to divide by the molar mass? ... Obviously the m/n is constant, so the whole conversation is moot

you do if you want to use the universal gas constant, otherwise you can use the specific gas constant which is just the universal gas constant divided by molar mass M if I remember correctly. Either way m and R cancel out so you're left with just pressure and temperature in this case.

 

SS what do you do for a living again?

 

Mechanical engineer by degree/license but I don't usually deal with that sort of stuff actually. Only remembered it correctly (use absolute temp units not F or C, add gauge and atmospheric pressure) because I took the licensing exam about a year ago and it was heavily tilted toward thermal stuff.

you do if you want to use the universal gas constant, otherwise you can use the specific gas constant which is just the universal gas constant divided by molar mass M if I remember correctly. Either way m and R cancel out so you're left with just pressure and temperature in this case.

 

 

 

Mechanical engineer by degree/license but I don't usually deal with that sort of stuff actually. Only remembered it correctly (use absolute temp units not F or C, add gauge and atmospheric pressure) because I took the licensing exam about a year ago and it was heavily tilted toward thermal stuff.

 

Ah, it's been a few years since I had to deal with that kind of thing, so I was really confused why you were using mass.

 

... back to your regularly scheduled NFL thread.

 

 

 

So how 'bout that Probowl?

So how 'bout that Probowl?

 

Did anything happen (lol)?

So how 'bout that Probowl?

 

what's that?

what's that?

Professional bowling.

Um, wow. The wife of Dolphins CB Brent Grimes went on a ridiculous anti-NFL Twitter rant.

 

http://dailydolphin.blog.palmbeachpost.com.../#__federated=1

 

Wow.

So how 'bout that Probowl?

All I know is that Adam Vinateri missed like 26 extra points or something, according to ESPN.

Marshawn Lynch is so annoying with the media. It's not funny anymore, just immature and unprofessional.

 

Today at media day, he answered almost every question with "i'm just here so I won't get fined"

Marshawn Lynch is so annoying with the media. It's not funny anymore, just immature and unprofessional.

 

Today at media day, he answered almost every question with "i'm just here so I won't get fined"

 

Pretty much.

Marshawn Lynch is so annoying with the media. It's not funny anymore, just immature and unprofessional.

 

Today at media day, he answered almost every question with "i'm just here so I won't get fined"

 

Its just simply who he is.

 

 

In other news Bears have named Clint Hurt the OLB coach. Pretty much confirms they'll run a 3-4 IMO. Fox didn't have one in Denver running the 4-3.

That's how I feel about the entire Seattle team. Mainly because their two mouthpieces are Lynch and Sherman, two of the most unlikable people in the league (and that's saying something).

Marshawn Lynch is so annoying with the media. It's not funny anymore, just immature and unprofessional.

 

Today at media day, he answered almost every question with "i'm just here so I won't get fined"

 

I'm torn about this. On one hand, he does make a lot of money knowing that being famous and dealing with media is part of the job description. On the other hand, meh, who cares. If he doesn't want to talk, go ask somebody else a question.

Its just simply who he is.

 

 

In other news Bears have named Clint Hurt the OLB coach. Pretty much confirms they'll run a 3-4 IMO. Fox didn't have one in Denver running the 4-3.

 

Christian Jones can absolutely thrive with this.

 

I think putting Bostic in the middle of a 3-4 will help his development as well.

I dont think forcing a guy to speak in front of the media who clearly has problems with it is the right way to go. Some guys have anxiety disorders about things like this, and some of them thrive on it. Expecting Lynch to start talking like Sherman by forcing him to take questions isnt really a good way to handle business.

Christian Jones can absolutely thrive with this.

 

I think putting Bostic in the middle of a 3-4 will help his development as well.

 

Where do you see Jones at? At first I was thinking he'd be nice on the inside (he could be) but looking back at scouting reports there was talk of his as 3-4 OLB.

 

Briggs has said with the new staff he'd like to return, what's everyones thoughts on that. I think he'd fit as an ILB, but only at the right price.

So Lynch is unlikeable because he doesn't say anything?

Edited January 27, 201511 yr by pettie4sox