Water lies between two horizontal parallel plates (a bottom plate and a top plate). The distance between plates is 1.63 mm. The bottom plate is fixed while the top plate is freely floating on the liquid. What pressure gradient must be applied to the water in order to move the top plate at a velocity of 0.6 m/s? Enter the absolute value of pressure gradient in Pa/m. HINT: Think about what shear stress is on the top plate and what the slope of the velocity profile is at the top plate.