At a temperature of 80C, a steel tire 12 mm thick and 90 mm wide that is to be shrunk onto a locomotive driving wheel 2 m in diameter just fits over the wheel, which is at a temperature of 25C. Determine the contact pressure between the tire and wheel after the assembly cools to 25C. Neglect the deformation of the wheel caused by the pressure of the tire. Assume a = 11.7 m/(m-C) and E = 200 GPa.