8.7 A sealed journal bearing is formed from concentric cylinders.

The inner and outer radii are 25 and 26 mm, the journal length is 100 mm, and it turns at 2800 rpm. The gap is filled with oil in laminar motion. The velocity profile is linear across the gap. The torque needed to turn the journal is 0.2 N m. Calculate the viscosity of the oil. Explain why the torque will increase, decrease, or stay the same with time.