A person who weighs 539 N is riding a 77-N mountain bike. Suppose the entire weight of the rider plus the bike is supported equally by the two tires. If the gauge pressure in each tire is 8.10 x 10^5 Pa, what is the area of contact between each tire and the ground?

To solve this problem, we can use the formula:

pressure = force/area

We know the total weight on the two tires is:

539 N + 77 N = 616 N

Since each tire supports an equal weight, the weight on each tire is:

616 N / 2 = 308 N

Now we can use the formula to find the area of contact for each tire:

8.10 x 10^5 Pa = 308 N / area

Solving for area, we get:

area = 308 N / (8.10 x 10^5 Pa) = 0.00038025 m^2

Therefore, the area of contact between each tire and the ground is 0.00038025 m^2.