For flowing water, what is the magnitude of the velocity gradient needed to produce a shear stress of 1.0 n/m2 ?

Shear stress = 1.0 N/m² (Pa)

For water, the dynamic viscosity = 10⁻³ Pa-s at 20°C.
The velocity gradient required = (Shear stress)/(Dynamic viscosity)
= (1.0 Pa)/( 10⁻³ Pa-s)
= 10³ 1/s

  10³  s⁻¹

It indicates no change in temperature and the process of matter changing its state