A sleeve 30 cm long encases a vertical rod 2.5 cm in diameter with uniform radial clearance of 0.005 cm. when the sleeve and the rod are immersed in a pool of oil with dynamic viscosity of 0.095 kg/m.s, the effective weight of the sleeve is 4.5N. how fast will the sleeve slide down the rod?
assumptions:
Neglect drag on the outer portion of the sleeve
Assume weight and viscous forces to be in equilibrium
Assume constant velocity gradient in the oil between the sleeve and rod