The pressure of a tire is 200 kPa as it is pulled out from the garage on a summer

day. The temperature in the morning is 10°C. By the afternoon the temperature

of the tire in the sun has reached 28°C. What is the pressure in the tire now?

Gay-Lussac's law states that if P=pressure and T=temperature, then P/T=P/T. Temperature must be in Kelvin, but pressure can be in any unit.

To convert Celsius into Kelvin, just add 273: 10+273=283K, and 28+273=301K.

So using the equation,

200kPa:283=? kPa:301

Solving this equation gives you about 212.72 kPa.