If p and are the net pressure and net shear stress acting on an infinitesimally small element (volume dx dy dz) moving along with the flow (velocity ( vec{V} )), what is the net work done on the system?

• A. ( rho ( nabla .(p vec{V} )+ nabla .( . vec{V})) )
• B. (((p vec{V})+( tau. vec{V}))dx ,dy ,dz )
• C. ( rho( nabla.(p vec{V})+ nabla.( tau. vec{V})) dx ,dy ,dz )
• D. (( nabla .(p)+ nabla.( tau))dx ,dy ,dz )