The record-read head for a computer disk-drive memory storage system rides above the spinning disk on a very thin film of air (the film thickness is \(0.25 \mu \mathrm{m}\) ). The head location is \(25 \mathrm{~mm}\) from the disk centerline; the disk spins at \(8500 \mathrm{rpm}\). The record-read head is \(5 \mathrm{~mm}\) square. For standard air in the gap between the head and disk, determine

(a) the Reynolds number of the flow,

(b) the viscous shear stress, 

(c) the power required to overcome viscous shear.