Describe in your own words the three strengthening mechanisms discussed in this chapter (grain size reduction, solid-solution strengthening, and strain hardening). Explain how dislocations are involved in each of the strengthening techniques.

On a average work day more than work place firs are reorted

The thermal expansion or contraction of a given metal is a function of the f a)-density b)-initial temperature c)- temperature difference d)- linear coefficient of thermal expansion e)- final temperature f)- original length

Amixture of gases consists of 0.4 kg of oxygen, 0.7 kg of carbon dioxide, and 0.2 kg of helium this mixture is maintained at 100 kpa and 27°c. determine: (a) the apparent molecular weight of this mixture the volume it occupies (b) the partial volume of the oxygen, and (c) (d) the partial pressure of the helium