A polymer viscoelastic behavior is to be modelled using standard solid model where a Maxwellmodelis connected in parallel with a spring. If the rheological constants are given as: $1=1\mathrm{.}5$ GPa, $2=0\mathrm{.}256$ GPa, $1=560$ GPa.$$a$.$ Estimate the creep of the polymer at $=0$and$=3600$seconds if it is kept under a constant stress, $=20$MPa for a length of $3600$ seconds. b$.$At $=3600$seconds, the $20$ MPa$$stress is unloaded and the material is left to recover the creep strain for additional time $=1200$seconds. Drive the expression for the recovery strain and evaluate the strain of the material at $=1000$seconds after the recovery.c$.$The materials experiences creep and recovery for a total time t$=4800$ seconds.Plot the creepand recoveryresponseof the material for the totaltimewith steps of $20$seconds increments