Poly(methyl acrylate) (PMA) is a rubbery polymer in most conditions, as its glass transition tem- perature Tg = 10 °C. PMA has a Kuhn length b = 15 Å and a Kuhn molar mass of Mo 495 g/mol. (a) If the entanglement molecular weight of PMA is Me ~ 11 kg/mol, estimate its tube diameter a. (b) PMA has a mass density P = 1.11 g/cm³. Estimate the volume of the Kuhn monomer vo. How does this compare to the published value of vo ~ 0.740 nm³? On the basis of the value Pe = 21, estimate the entanglement molecular weight. (c) The length of the confining tube can be expressed as L ~bN/√Ne. Calculate the length of the tube, as well as the reptation time for the polymer chain if it has a monomer friction coefficient so = 3 x 10^-10 g/s.