Recall that, under standard conditions, the metalloid element Polonium (Po) exhibits the simple cubic crystal structure, and is known to be brittle. If a single crystal of Po is loaded in tension along the [001] axis of the crystal, which of the following candidate slip systems features a resolved shear stress of zero ?
a. (001) [100]
b. (001) [010]
c. (010) [100]
d. (010) [001]
e. (100) [010]
f. (100) [001]

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

A3-mm-thick panel of aluminum alloy (k 177 w/m-k, c 875 j/kg-k and ? = 2770 kg/m) is finished on both sides with an epoxy coating that must be cured at or above t,-150°c for at least 5 min. the production line for the curing operation involves two steps: (1) heating in a large oven with air at ts,0-175°c and a convection coefficient of h, 40 w/m2. k, and (2) cooling in a large chamber with air at 25°c and a con- vection coefficient of he 10 w/m2.k. the heating portion of the process is conducted over a time interval te which exceeds the ime required to reach 150°c by 5 min (h = r + 300 s). the coating has an emissivity of ? = 0.8, and the temperatures of the oven and chamber walls are 175 and 25°c, respectively. if the panel is placed in the oven at an initial temperature of 25°c and removed from the chamber at a safe-to-touch tempera ture of 37°c, what is the total elapsed time for the two-step curing operation?

When subject to a steady load (within elastic range) over a long period of time, what is the major difference in material behavoir between steel and plastic?