5.68 A cylindrical casting has a diameter of 300 mm and a length of 1 m. Another casting of the same metal is rectangular in cross section, with a width-to-thickness ratio of 3, and has the same length and cross- sectional area as the round casting. Both pieces are cast under the same conditions. The cylindrical casting solidifies in three minutes. How long does the rectangular cross section casting take to solidify

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

Burgers vector is generally parallel to the dislocation line. a)-true b)-false

Plot schematically the tensile stress versus strain curves for a typical thermoplastic material at a temperature below its glass transition temperature (tg and at a temperature above its tg, respectively. do the same for a typical thermosetting material. list in a table any differences or similarities between the two materials at t> tg and t < tg, respectively, and relate them to the structures of the two types of polymers