Excercice 2 A shaft with outside diameter of 18 mm turns at 20 revolutions per second inside a stationary journal bearing 60 mm long. A thin film of oil 0.2 mm thick fills the concentric annulus between the shaft and journal. The torque needed to turn the shaft is 0.0036 N m. Estimate the viscosity of the oil that fills the gap. (3 Oil D = 18mm T 2=60mm- t=0.2 mm