oil flows in the negative z-direction between two infinite parallel plates under the influence of gravity. the flow is steady, incompressible, and laminar. the gap distance between the plates is h. there is no applied pressure gradient in the flow (i.e., the flow is driven solely by gravity). starting with the differential forms of conservation of mass and momentum (in the z-direction), derive the expression for the velocity profile across the gap. take the centerline to be x
