Compare the pressure exerted by the tires of your car on the road with the air pressure in the tires. For this project, you need to know the weight of your car, which you can get from a manual or a dealer. You divide the weight by 4 to get the approximate weight held up by one tire.
You can closely approximate the area of contact of a tire with the road by tracing the edges of the tire contact on a sheet of paper marked with 1-inch squares beneath the tire.
After you calculate the pressure of the tire against the road, compare it with the air pressure in the tire. Are they nearly equal? If not, which is greater?