For each of the plane stress states listed below, draw Mohr's circle and use it to determine the:
- principal normal stresses:
- angle to the principal normal stress coordinate system
- principal shear stresses
- angle to the principal shear stress coordinate system
(a) $\sigma_x = 20$ kpsi, $\sigma_y = -10$ kpsi, $\tau_{xy} = -8$ kpsi
(b) $\sigma_x = 16$ kpsi, $\sigma_y = 9$ kpsi, $\tau_{xy} = 5$ kpsi
(c) $\sigma_x = 10$ kpsi, $\sigma_y = 24$ kpsi, $\tau_{xy} = 6$ kpsi
