[Racer26]

I did wonder if temperature shift might have been why the GTRWest balls seemed overinflated, especially early on Friday.

Crescent's fieldhouse, being essentially a big tent with hockey-arena style infrared heating, might have been colder when the balls were being filled in preparation for the event, and then as the arena warmed up (because the heaters had been on and we added 900 people to the mix), the balls might have expanded.

It would be interesting to see how much temperature affects the ball diameter at different pressures. I wonder how static the temperature has to be to maintain a relatively consistent ball diameter.

The fieldhouse was experiencing fairly large swings in air temperature because of the nature of its heating, I wonder if that would have been enough to change diameter of the balls significantly while we were playing.

EDIT:

I think this would be covered under ideal gas law too.

PV = nRT

n, and R are constant since we're not adding or subtracting any air from the ball. I don't know that P is constant, but assuming it is:

V1 = 8181.23in^3 (the volume of a 25" sphere)
T1 = 20degC (293.15K)
T2 = 21degC (294.15K)

(V1/T1) = (V2/T2)

(8181.23/293.15) = V2/294.15
294.15*(8181.23/293.15) = 8209.138in^3

8209.138 = (4/3)pi * (r^3)
8209.138 /((4/3)*pi) = r^3
1959.787336 = r^3
1959.787336^(1/3) = r
12.514in = r

Changing air temp from 20C to 21C would add 0.028" to the diameter of a ball. (If T1 = 15C and T2 = 22C, the ball changes 0.200" in diameter)

Did I do that right? It doesn't seem right to me. I think changing temperature will also change P.