A car tire gauge is used to fill a tire to a gauge pressure of 42.5 lb/in2 on a cold morning when the temperature is -16 C. Atmospheric pressure is 14.7 lb/in2 and 0 C = 273 K.
What would the tire gauge read when the tire has been heated up to 44.2 C?
P2 = P1 (atmospheric pressure) + ϱgh (gauge pressure)
P1/T1 = P2/T2
The Attempt at a Solution
P2 = (14.7 lb/in2 + 42.5 lb/in2) = 57.2 lb/in2
I don't really know if this is even the right first step. I just recognized that gauge pressure is ϱgh. What should I do next?