A mild steal (1% carbon), 2 cm OD shaft, rotating in 20?C air at 20,000 rev/min, is attached to two bearings 0.7 m apart. If the temperature at the bearings is 90?C, determine the temperature distribution along the shaft. Hint: Show that for the high rotational speeds equation (5.35) approaches: NuD = 0.086 (π D2w/v)0.7GIVENA mild steel shaft rotating in air between two bearingsShaft diameter (D) = 2 cm = 0.02 mRotational speed (w) = 20,000 rev/minAir temperature (T??) = 20?CLength of shaft (L) = 0.7 mBearing temperatures (Tb) = 90?CASSUMPTIONSThe rod has reached steady stateRadiation is negligibleThe shaft ishorizontal

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T = 90°C T=20°C