A certain polymer sample can be represented by a single Maxwell element that is composed of a dashpot attached, in series, to a spring. The dashpot has viscosity, , and the spring has the modulus, G. (a) obtain the governing differential equation for a Maxwell element. Explain each step you take. (b) At t=0, a constant strain 0 is applied and hold there. The time evolution of the stress in the sample is measured. Plot strain-time and stress-time graphs and obtain an expression for the relaxation modulus (G(t)). (c) At t=0, a constant stress 0 is applied until time t=t1 when the stress is removed suddenly. You measure the strain during the experiment. Plot strain-time and stress-time graphs and obtain an expression for creep compliance (J(t)) for 0t1. (d) When a 15cm-long polymer sample is subjected to a constant tensile load of 20kPa, it stretches to a total length of 18.5cm in 1500s. Upon removal of the load, the sample recovers only to 16.85cm. By representi a Maxwell element, estimate the time it would take for an identical (un relax to 0.85 its original stress when a constant elongation of 50% is app