You use a tire gauge to measure the air pressure in a bicycle tire. The gauge reads 38.5 psi. What is the absolute pressure in the tire in kilopascals?

Answer 1

This question requires a knowledge of conversion factors. We need to convert psi (pounds per square inch) to kilopascals (kPa). Here are two ways to do this:

Use 1 atm = 14.7 psi and 101.325 kPa = 1 atm

38.5 psi x 1 atm / 14.7 psi x 101.325 kPa / atm = 265 kPa

Use 1 psi = 6.895 kPa

38.5 psi x 6.895 kPa / psi = 265 kPa