Below are shown and

labeled three schematic specific volume vs. temperature curves that may be

displayed by various types of materials. Which one would be typical of a

semi-crystalline polymer?

Below are shown and

labeled three schematic specific volume vs. temperature curves that may be

displayed by various types of materials. Which one would be typical of a

semi-crystalline polymer?

Given the following atomic weights and structure schematic, what is the repeat unit weight of polystyrene?

What factors influence

mechanical properties of semicrystalline polymers?

Predict the crystal structure for MgO, on the basis of the ionic charge and ionic radii given in the table below.

Calculate the fraction of lattice sites that are Schottky defects for magnesium oxide at its melting temperature (2850°C). Assume an energy for defect formation of 2.5 eV.

Using the phase diagram below, for an alloy with the composition 30 wt% Pb-70 wt% Mg at 200°C, determine the phases present and the phase compositions (in wt% Pb) 

What is the maximum stress at the tip of an internal crack having a radius of curvature of 3×10^-4 mm and a crack length of 2×10^-2 mm when a tensile stress of 60 MPa is applied?

An alloy of composition 60 wt% Pb - 40 wt% Mg is heated to 300°C.  Using the same phase diagram for Mg-Pb as above, what is the composition (in wt% Pb) of the α phase? 

Your final answer should be in the format **