For some viscoelastic polymers that are subjected to stress relaxation tests, the stress decays with time according to s(t) = s(0) expa - t t b (15.10) where s(t) and s(0) represent the time-dependent and initial (i.e., time 0) stresses, respectively, and t and t denote elapsed time and the relaxation time, respectively; t is a time-independent constantcharacteristic of the material. A specimenof a viscoelastic polymer whose stress relaxationobeys Equation 15.10 was suddenly pulled in tensionto a measured strain of 0.5; the stress necessaryto maintain this constant strain was measuredas a function of time. Determine Er(10) for thismaterial if the initial stress level was 3.5 MPa (500psi), which dropped to 0.5 MPa (70 psi) after 30 s.

Anthony Lovill BE1500 Quiz 10 November 29, 2016 %This function file calculates the maximum number within a given cell %array. function [maxNum]= Quiz_10(a); [m,n]=size(a); i=1; k=1; while i<=m j=1; while j<=n c=class(a{i,j}); if strcmp(c,'double') for t=1:length(a{i,j}) vec=a{i,j}; g(k)=vec(t); k=k+1; end elseif strcmp(c,'cell') if strcmp(c,'double') for t=1:length(a{i,j}) vec=a{i,j}; g(k)=vec(t); k=k+1; end end else end j=j+1; end i=i+1; end i=1; j=2; d=length(g); while j<=d if g(i)>g(j) g(j)=g(i); g(i)=g(j); end j=j+1; i=i+1; end maxNum=g(d); disp(maxNum) >> Q