a.
b.
The metal obey this law for values of strain until 0.05, where we have a linear relationship (each increase of 0.01 in the strain causes an increase of 100 in the stress). After this point, we don't have a linear relationship anymore.
c. Since an increase of 0.01 in the strain causes an increase of 100 in the stress, the slope is:
Now, calculating the coefficient b (y-intercept), we have:
So the equation is:
d.
The maximum value of stress is 560, and occurs at strain = 0.07.