## Tire Pressure

The manufacturer's sticker on a car door panel says that the mass of the car is 1550 kg and the tires should be inflated to a gauge pressure of 186.2 kPa (27 psi). What is the area of

*each tire*that is in contact with the ground if all four tires are inflated according to the manufacturer's specification? Assume that the weight of the car is evenly distributed among the four tires.**0.0204 m^2**## **Approach**

This problem is asking for the area of each tire that is in contact with the ground when all the tires are inflated according to the manufacturer's specification of 186.2 kPa (27 psi). The weight of the car is the force that is exerted on the tires and since pressure is force divided by area, the total area (of all four tires) in contact with the ground can be calculated.

## **Solution**

Since function NoFontMessage P=AF=Amg, the total area is A=Pmg=15509818621000 = 0.08158m2. Thus the area of each tire that is in contact with the ground is 0.08158/4 = 0.0204m 2.