Answer:
(A) The pressure in both tire is 17.97 N/cm^2 or 179,667 Pascals or 26.1 psi.
(B) It is difficult to predict what will happen with the area of the tires in contact with the Earth the event of a puncture. Higher, perhaps, since the tire flattens out, adding surface area.
Step-by-step explanation:
Given
55kg
15 cm^2 per tire, with 2 tires
g = 9.8 N/kg
Calculate the force of the bicycle on the Earth
Force = Mass*Acceleration
Force = (55kg)*(9.8 N/kg)
Force = 539 N
Calculate the force per cm^2 contact area
Area = 2*(15 cm^2) = 30 cm^2
Pressure = 539N/30 cm^2
Pressure = 17.97 N/cm^2
Change to a standard SI unit for pressure, the Pascal [For fun, the problem doesn't specify units]
Since 1 Pascal = 1 N/m^2, and
1 cm^2 = 0.0001 m^2
Pressure = (17.97 N/cm^2)*(1 cm^2/0.0001 m^2)
Pressure = 179,667 Pascals
For the non-SI crew
1 Pascal = 0.000145 psi
Pressure = 26.1 psi
(A) The pressure in both tire is 17.97 N/cm^2 or 179,667 Pascals or 26.1 psi.
(B) It is difficult to predict what will happen with the area of the tires in the event of a puncture. The flattened tire will spread out a little, so one might say the contact area increases. But the intent of the question is not clear. Good luck.