1. Chances are that the specimens failed somewhere other than directly in the middle. What determines where a specimen fails?
2. For the steel specimen compare the stress in the bar at rupture, as computed from the area at the break, with the ultimate strength. Why isn't the actual area of the fractured crosssection a suitable basis for defining strength?
3. Why is it often difficult to evaluate the elastic limit?
4. What is the effect of poor alignment of the specimen? Why does a specimen that is properly aligned provide a more accurate estimate of the tensile strength compared to the estimate provided from results from a test where the specimen was not accurately aligned?
5. Why would a stress-strain diagram be preferable to a load-elongation diagram for presenting the results of a tension test?
6. Why is it important to know the gage length when using percent elongation information?
7. Explain why the percent elongation in a one inch gage section may exceed that of an 8 inch gage section.
8. Can the elongation of a specimen be determined accurately by measuring the movement of the test machine cross head? Why?