Details pertaining to an orthogonal mental cutting process are given below.
$\begin{array}{ll} \text{Chip thickness ratio} & 0.4 \\ \text{Undeformed thickness} & 0.6 \text{ mm} \\ \text{Rake angle} & +10^{\circ} \\ \text{Cutting speed} & 2.5 \text{ m/s} \\ \text{Mean thickness of primary shear zone} & 25 \text{ microns} \end{array}$
The shear strain rate in $s^{-1}$ during the process is
- $0.1781 \times 10^5$
- $0.7754 \times 10^5$
- $1.0104 \times 10^5$
- $4.397 \times 10^5$