An aluminum shell is wrapped around and fully bound to a steel shell. Aluminum has a young’s modulus of 70 GPa and a coefficient of thermal expansion of 23.6*10- 6 /°C and steel has a Young’s modulus of 200 GPa and a coefficient of thermal expansion of 11.7*10-6 /°C. If it is unstressed at 25° determine the stress when the temperature is raised to 200°. Consider only axial changes.

Asolid cylinder is concentric with a straight pipe. the cylinder is 0.5 m long and has an outside diameter of 8 cm. the pipe has an inside diameter of 8.5 cm. the annulus between the cylinder ad the pipe contains stationary oil. the oil has a specific gravity of 0.92 and a kinematic viscosity of 5.57 x 10-4 m2/s. most nearly, what is the force needed to move the cylinder along the pipe at a constant velocity of 1 m/s?