A prismatic bar with a length L = 1 m and cross-sectional area A = 1200 mm2 is supported at the ends. The bar is then subjected to a temperature increase of ?T = 25?C. Calculate the complete state of stress acting on an inclined section rs that is cut through the bar at an angle \theta = 45?. Use E = 200 GPa and the coefficient of thermal expansion \alpha = 12 x 10-6 / ?C.

Describe one experiment in which the glass transition temperature and melting temperature of a totally amorphous thermoplastic material can be determined. show the relevant experimental results in a diagram which should be properly annotated with the two temperatures clearly marked. what is likely to happen to the curve in the diagram if the amorphous polymer is replaced by a thermosetting type?