Water as much as 0.002kg/s at a temperature of 18 °C Flows into a tube with a flow that has been formed hydrodynamically. The inside diameter of the pipe is 1.5 cm and the surface temperature in the pipe is uniform at 125°C. Calculate the length of the pipe required to heat the water to become 82 °C

Air at 1 atm and 40C flows in a 8-cm-diameter pipe at a rate of 2500 L/min. The friction factor determined from the Moody chart is 0.027. The required power input to overcome the pressure drop for a pipe length of 150 m is: (a) 310 W (b) 188 W (c) 132 W (d) 81.7 W (e) 35.9 W

The fluid condition at the inlet and exit of a horizontal convergent nozzle is analysed. The nozzle is operating steadily and heat loss is assumed negligible. If the specific enthalpy of fluid and velocity of fluid at the inlet are 3,317 kJ/kg and 282 km/hr respectively. At the exit the specific enthalpy of fluid is 2,646 J/kg. Calculate the exit area (in mm2)of the nozzle when the specific volume at the nozzle exit is 0.6 m3/kg at the inlet area of 0.23 m2 and the specific volume at the inlet is 0.31 m3/kg.    You do not need to include the unit for this question.

Water with a mass flow rate of 0.002 kg/s at 18oC flows inside a tube while the flow is already developed hydrodynamically. The inner diameter of the tube is 1.5 cm, and the inner pipe wall temperature is maintained uniformly at 125oC. Calculate the required tube length to increase the water temperature to 82oC.