Question

The pressure in car tires is often measured in pounds per square inch (lb/in.2), with the recommended pressure being in the range of 25 to 45 lb/in.2. Suppose a tire has a pressure of 27.0 lb/in.2 . Convert 27.0 lb/in.2 to its equivalent in atmospheres.

Answer 1

1.36 atm

Step-by-step explanation:

First, we have to transform lb and in² into the International System of Units.

• The international unit for force is the Newton. The equivalence (based on Earth's gravity) is 1 lb = 4.448 N.
• The international unit for area is the m². The equivalence is 1 m² = 1550 in².
• The resulting unit is known as Pascal. 1 Pa = 1 N/m².

`(27.0lb)/(in^(2)) .(4.448N)/(1lb) .(1550in^(2))/(1m^(2) ) =1.38 * 10^(5) Pa`

The equivalence between Pascal and atm is 101,325 Pa = 1 atm. Then,

`1.38 * 10^(5) Pa.(1atm)/(101,325Pa) =1.36atm`