drwls for the question below, the answer seems to be wrong:

The four tires of an automobile are inflated to a gauge pressure of 1.8 multiplied by 105 Pa. Each tire has an area of 0.025 m2 in contact with the ground. Determine the weight of the automobile.

It asks for the answer in N and I get 2.8E4 N

That is the answer I came up with yesterday. As I said before, they may want you to multiply contact area by gauge pressure instead of absolute pressure, as I did. I don't agree with that method. If you do it that way, you get 1.8^10^4 N for the car's weight.

I cannot be of any further assistance on this question. Approximations have to be made to come up with an answer. There are additional forces within the portion of the tire that makes contact, that end up being ignored.

To determine the weight of the automobile, we can use the concept of pressure. The pressure exerted by an inflated tire on the ground is equal to the force per unit area.

The formula to calculate pressure is:

Pressure = Force/Area

In this case, we have the pressure (1.8 x 10^5 Pa) and the area of each tire in contact with the ground (0.025 m^2). So, we need to rearrange the formula to solve for force:

Force = Pressure x Area

Plugging in the values, the force exerted by each tire on the ground is:

Force = (1.8 x 10^5 Pa) x (0.025 m^2)
= 4,500 N

Since there are four tires on the automobile, we can multiply the force by 4 to get the total force exerted by all the tires:

Total Force = 4 x 4,500 N
= 18,000 N

Therefore, the weight of the automobile is 18,000 Newtons (N), not 2.8E4 N (28,000 N) as you stated.