The gauge pressure in your car tires is 2.20 x 10^5 N/m^2 at a temperature of 35.0°C when you drive it onto a ferry boat to Alaska. What is their gauge pressure (in atm) later, when their temperature has dropped to - 38.0°C? (Assume that their volume has not changed.)

1.425 atm

Explanation:

Gauge pressure, P1' = 2.20 x 10^5 N/m^2 = 2.178 atm

Absolute pressure P1 = P1' + Po

where, Po be the atmospheric pressure

P1 = 2.178 + 1 = 3.178 atm

T1 = 35 degree C = 35 + 273 = 308 k

T2 = - 38 degree c = - 38 + 273 = 235 k

let final absolute pressure is P2. Use

P1 / T1 = P2 / T2

3.178 / 308 = P2 / 235

P2 = 2.425 atm

So, the final gauge pressure = 2.425 - 1 = 1.425 atm