A material is loaded elastically under plane stress condition given by the following tensor:
\[\left[ {\begin{array}{*{20}{c}} 1 \\ 0 \end{array}\begin{array}{*{20}{c}} 2 \\ 1 \end{array}\begin{array}{*{20}{c}} 0 \\ 0 \end{array}} \right]\]
The modulus of rigidity is 25 MPa. The maximum elastic engineering strain is