A steel rod 15 m long is at a temperature of 15°C. The values of α = 12 × 10-6m and E = 200 GN/m2 are adopted. When the temperature is raised to 65°C, what is the free expansion of the length; and if this expansion of the rod is fully prevented, what is the temperature stress produced?

A steel rod 15 m long is at a temperature of 15°C. The values of α =

1.	A steel rod 15 m long is at a temperature of 15°C. The values of α = 12 × 10-6m and E = 200 GN/m2 are adopted. When the temperature is raised to 65°C, what is the free expansion of the length; and if this expansion of the rod is fully prevented, what is the temperature stress produced?
A.	5 mm and 120 MN/m2
B.	9 mm and 120 MN/m2
C.	5 mm and 150 MN/m2
D.	9 mm and 150 MN/m2
Answer» C. 5 mm and 150 MN/m2