When the temperature of an automobile tire is 20°c, the pressure in the tire reads 32 psi on a tire gauge. (the gauge measures the difference between the pressures inside and outside the tire.) what is the pressure when the tire heats up to 40°c while driving? you may assume that the volume of the tire remains the same and that atmospheric pressure is a steady 14 psi.

The initial pressure in the tire is given by the difference between the gauge pressure and the atmospheric pressure:

Let's also convert the initial and final temperature of the tire into Kelvin:

We know that the volume of the tire remains the same, so we can use the fact that the ratio between pressure and temperature of the tire remains constant:

which can be rewritten as

from which we can find the value of the final pressure, p2:

And converted back into PSI,