- #1
thetexan
- 269
- 13
If I take a balloon and tie it off prior to blowing it up I have a flaccid balloon with atmospheric pressure both inside and outside the balloon...say 14.7 psi.
Now if I blow up the balloon I am working against the elasticity of the rubber and it requires effort to do so. I blow more and more volume into the balloon and it requires more psi inside than outside to press outward against the elastic rubber and hold a certain size of balloon.
If the NFL's rules call for 12.5 to 13.5 psi that's less than 14.7 psi ambient atmosphere. Shouldn't the football shrink under the excessive outer pressure until there is equilibrium leaving 14.7 both inside and out?
I know that volume is the key but I don't understand. When they say 13.5 do they mean 13.5 psi greater than the 14.7 ambient or a total of 28.2?
If so does that mean that our little pump meters are reading psi above ambient?
Tex
Now if I blow up the balloon I am working against the elasticity of the rubber and it requires effort to do so. I blow more and more volume into the balloon and it requires more psi inside than outside to press outward against the elastic rubber and hold a certain size of balloon.
If the NFL's rules call for 12.5 to 13.5 psi that's less than 14.7 psi ambient atmosphere. Shouldn't the football shrink under the excessive outer pressure until there is equilibrium leaving 14.7 both inside and out?
I know that volume is the key but I don't understand. When they say 13.5 do they mean 13.5 psi greater than the 14.7 ambient or a total of 28.2?
If so does that mean that our little pump meters are reading psi above ambient?
Tex