$3$A$.$ By means of appropriate equations and sketches discuss the WLF and briefly describe how the universal constants $C_1$ and $C_2$ can be measured experimentally. In your answers, state the equipment to be used, the experimental procedure, the data to be collected, the dependent and independent variables and a hypothetetical graphical analysis of your data

B$.$ The viscosity of polyisobutylene of molecular weight of $150,000\frac{g}{m}$ole is $9\mathrm{.}50{10}^{7}Pa.$s at $298K.$ The temperature dependence of viscosity is described by the WLF equation; $C_1=8\mathrm{.}86,C_2=101\mathrm{.}6,$ and $T_g=298K.$ Determine polyisobutulene viscosity at $400K.$