le) Name four methods used for strengthening of metals. What is the common principle that these methods rely on to make a metal stronger. 2. For the data given below

(3) Metals tend to expand when heated and contract when cooled. If a clock has a pendulum made of a bob attached to the end of a metal rod (as opposed to the string we used in our lab), completely describe the effect that temperature would have on the accuracy of the clock (i.e., would the clock run too fast or too slow) and why? k

1. Explain in 1-3 bullets how as a practicing engineer you determine the yield strength of a metal from a tensile stress-strain curve. 2. Explain what is happening at the yield strength for a metal from a physical standpoint in 1-3 bullets. (e.g. what are the atoms doing?)