Clearly label where af corresponds to in the figure below st
     Clearly label where a-f corresponds to in the figure below (stress-strain curve), and describe the significance of each point/region.  Elastic region  Plastic region  Linear portion of the stress-strain curve (what does it tell us?)  Ultimate stress (what does it tell us?)Strain to failure (what does it tell us?)  Strain energy density (what does it tell us?)  Elastic region  Plastic region  Linear portion of the stress-strain curve (what does it tell us?)  Ultimate stress (what does it tell us?)  Strain to failure (what does it tell us?)  Strain energy density (what does it tell us?)  
  
  Solution
a) Elastic Region AC
b)Plastic Region CE
c)Its the area where Hooke\'s law is obeyed. In this area , after the stress is removed ,the object regains it original shape.
d) The maximum stress material can bear before failure

