A steel spacing bar of length 1.6 m is assembled in a structure whilst the temperature of thestructure is 20°C. (a) What will be the change in length of the

bar (in mm) if the temperature rises to 60°C and the bar is allowed to expand? (b) What will be the stress in the bar if, during the temperature rise, free expansion is prevented? (c) If the factor of safety is to be 3, what will be the ultimate strength?