Figure (2) 23/ A bearing, which can be approximated as two flat plates separated by a thin film of lubricant, Figure (2), is fo to offer a resistance of (400 N) when SAE 30 oil is used as the lubricant and the relative velocity between plates is (10 m/s). If the area of the plates A is (0.1 m), determine the clearance between the plates. Assume absolute viscosity of SAE 30 oil as (0. 3345 Pa.s).

Problem 2 The apparatus sketched in the figure below serves as a viscometer i.e. it can be used to measure the viscosity of a liquid. In the drawing, D is a large reservoir containing a viscous liquid A and E is a cylindrical tube of radius R, open at both ends, surrounding and coaxial with B, which is a cylindrical "bob" of radius êR that is dragged up through the fluid by a frictionless pulley system (C) utilizing a weight W. Determine a design equation that relates the viscosity of the liquid to the geometry of the system and the weight W. Hint: you can assume that the length of the cylindrical tube is sufficiently long for the flow to reach steady state. W E D B

6. A hydraulic lift (see below) of the type commonly used for greasing automobiles consists of a 280.00 mm diameter ram which slides in a 280.18 mm-diameter cylinder, the annular space being filled with oil film of thickness t = 0.09 mm, having a viscosity 0.3612 kg/(m s). If the rate of travel of the ram is v= 0.22 m/s, find the frictional resistance when 2 m of the ram is engaged in the cylinder. Take the weight of ram as 500 N. Ram Oil film -Fixed cylinder