Geocritter wrote:
I think I’m slowly getting there. If atmospheric pressure at sea level is 14.7psi (empty tire) and the tire holds 2.37cu ft empty, then solving for X where X equals the volume of gas in the tire at 70psi using this formula:
2.37/14.7 = X/70
resulting in X = 11.3cu ft of gas (nitrogen) in the tire to achieve a pressure of 70psi.
I absolutely don’t trust my math, can someone verify?
Steve
Not exactly, but close. You're confusing "absolute" pressure (psia) with gauge pressure (psig). If you put a tire gauge on an empty tire (only atmospheric pressure), it will read 0 psi, not 14.7 psi. So, 70 psig is actually 84.7 psia. Otherwise, you are correct. By the ideal gas law, pressure is proportional to the amount of gas in the container.
