When viewed from above, if a car has an area A1, what is the expression for its weight, considering tire pressure and contact area?

To understand why the expression for the weight of a car, considering tire pressure and contact area, is given as 4PrA2, we need to explore the relationship between weight, pressure, and area.

In physics, pressure is defined as force per unit area, or P = F/A, where P is pressure, F is the force (in this case, the weight of the car), and A is the area over which the force is applied (the contact area of the tires on the ground). When you rearrange this equation to solve for force (F), it becomes F = P * A.

In the context of the question, the weight of the car acts at each of its four tires, and the area A1 is representative of the contact area of one tire with the road. Hence, each tire can be associated with its own contact area (which we'll denote as A2 for clarity). Adding the influence of all four tires, the total contact area is 4A2.

Moreover, the weight of the car can also be expressed by incorporating the tire pressure (P). Thus, the overall weight of the car becomes:

Weight = Pressure * Total Contact Area

Weight = P * (4A2)

Therefore, when