Define longitudinal strain and shearing (tangential) stress and write their formulas. What is the magnitude of hydraulic stress?

• A
  $\text{Longitudinal strain} = \Delta L / L$, $\text{Shearing stress} = F/A$, $\text{Hydraulic stress} = F/A$
• B
  $\text{Longitudinal strain} = L / \Delta L$, $\text{Shearing stress} = A/F$, $\text{Hydraulic stress} = P$
• C
  $\text{Longitudinal strain} = \Delta L / L$, $\text{Shearing stress} = F_{\text{tangential}}/A$, $\text{Hydraulic stress} = P = F/A$
• D
  $\text{Longitudinal strain} = \Delta L / L$, $\text{Shearing stress} = F/A$, $\text{Hydraulic stress} = 0$