Abearing uses sae 30 oil with a viscosity of 0.1 n·s/m2. the bearing is 30 mm in diameter, and the gap between the shaft and the casing is 2.0 mm. the bearing has a length of 3 cm. the shaft turns at ω = 350 rad/s. assuming that the flow between the shaft and the casing is a couette flow, find the torque required to turn the bearing.

Amass of m 1.5 kg of steam is contained in a closed rigid container. initially the pressure and temperature of the steam are: p 1.5 mpa and t 240°c (superheated state), respectively. then the temperature drops to t2= 100°c as the result of heat transfer to the surroundings. determine: a) quality of the steam at the end of the process, b) heat transfer with the surroundings. for: p1.5 mpa and t 240°c: enthalpy of superheated vapour is 2900 kj/kg, specific volume of superheated vapour is 0. 1483 m/kg, while for t 100°c: enthalpy of saturated liquid water is 419kj/kg, specific volume of saturated liquid water is 0.001043m/kg, enthalpy of saturated vapour is 2676 kj/kg, specific volume of saturated vapour is 1.672 m/kg and pressure is 0.1 mpa.

Fluids at rest possess no flow energy. a)- true b)- false

During a steady flow process, the change of energy with respect to time is zero. a)- true b)- false