Hot air enters a rectangular duct (20-cm-wide, 25-cm-high, and 5-m-long) at 100 kPa and 60 o C at an average velocity of 5 m/s. While air flows through the duct, it gets cool down (loses energy) so that air leaves the duct at 54 o C. Determine the rate of heat loss from the air under steady condition.

Explain the difference laminar and turbulent flow. explain it with the shear stress and the velocity profiles.

For the closed feedwater heater below, feedwater enters state 3 at a pressure of 2000 psia and temperature of 420 °f at a rate of ix10 ibhr. the feedwat extracted steam enters state 1 at a pressure of 1000 psia and enthalpy of 1500 btu/lbm. the extracted er leaves at an enthalpy of 528.7 btu/lbm steam leaves as a saturated liquid. (16) a) determine the mass flow rate of the extraction steam used to heat the feedwater (10) b) determine the terminal temperature difference of the closed feedwater heater

The filament of an incandescent lamp has a temperature of 2000k. calculate the fraction of radiation emitted in the visible light band if the filament is approximated as blackbody