Water at 50 °C enters a rectangular duct of 40 mm x 20 mm cross-section and 4 m long duct with a velocity of 0.8 m/s. The duct walls are maintained at a constant temperature of 90 °C. Determine the...

Extracted text: Water at 50 °C enters a rectangular duct of 40 mm x 20 mm cross-section and 4 m long duct with a velocity of 0.8 m/s. The duct walls are maintained at a constant temperature of 90 °C. Determine the heat transfer coefficient and the total amount of heat transferred if exit water temperature is 70 °C.